First Mining Gold Corp.

No securities regulatory authority has expressed an opinion about these securities and it is an offence to claim otherwise. This prospectus supplement together with the short form base shelf prospectus dated June 24, 2019 to which it relates, as amended or supplemented and each document incorporated by reference into the short form base shelf prospectus for purposes of the distribution of the securities to which this prospectus supplement pertains constitutes a public offering of these securities only in those jurisdictions where they may be lawfully offered for sale and therein only by persons permitted to sell such securities.

Information has been incorporated by reference in this prospectus supplement and in the accompanying short form base shelf prospectus dated June 24, 2019 to which it relates, from documents filed with securities commissions or similar authorities in Canada . Copies of the documents incorporated herein by reference may be obtained on request without charge from the General Counsel & Corporate Secretary of First Mining Gold Corp. at Suite 2070 – 1188 West Georgia Street, Vancouver, British Columbia V6E 4A2, and are also available electronically at www.sedar.com.

The securities offered hereby have not been and will not be registered under the U.S. Securities Act of 1933, as amended (the “U.S. Securities Act”), or any state securities laws. The securities may not be offered or sold in the United States of America, its territories and possessions, any state of the United States or the District of Columbia (collectively, the “United States” or “U.S.”) or to, or for the account or benefit of, U.S. persons (as such term is defined in Regulation S under the U.S. Securities Act (“U.S. Persons”)) unless exemptions from the registration requirements of the U.S. Securities Act and applicable state securities laws are available and to the extent permitted by the Underwriting Agreement (as defined herein). This prospectus supplement does not constitute an offer to sell or a solicitation of an offer to buy any of the securities offered hereby within the United States. See “Plan of Distribution”.

PROSPECTUS SUPPLEMENT

(to the Short Form Base Shelf Prospectus dated June 24, 2019)

New Issue

August 19, 2020

==> picture [360 x 114] intentionally omitted <==

C$25,000,000 50,000,000 Units

This prospectus supplement (the “ Prospectus Supplement ”), together with the accompanying short form base shelf prospectus dated June 24, 2019 (the “ Base Shelf Prospectus ” and together with the Prospectus Supplement, the “ Prospectus ”) qualifies the distribution (the “ Offering ”) of 50,000,000 units (the “ Offered Units ”) of First Mining Gold Corp. (the “ Company ”) at a price of C$0.50 per Offered Unit (the “ Offering Price ”). The Offering is being made pursuant to an underwriting agreement dated August 19, 2020 (the “ Underwriting Agreement ”) among the Company and Cormark Securities Inc. as lead underwriter (the “ Lead Underwriter ”), together with BMO Nesbitt Burns Inc. (together with the Lead Underwriter, the “ Canadian Underwriters ”) and H.C. Wainwright & Co., LLC (“ HCW ” and together with the Canadian Underwriters, the “ Underwriters ”), pursuant to which the Offered Units will be offered for sale in all provinces of Canada (other than Québec) through the Canadian Underwriters in accordance with the terms of the Underwriting Agreement. HCW is not registered as a dealer in any Canadian jurisdiction and accordingly, will not, directly or indirectly, solicit offers to purchase or sell Offered Units in Canada. The Offering Price has been determined by arm’s length negotiation between the Company and the Underwriters, with reference to the prevailing market price of the common shares of the Company (the “ Common Shares ”).

Each Offered Unit is comprised of one Common Share (each, a “ Unit Share ”) and one-half of one Common Share purchase warrant (each full warrant, a “ Warrant ”). Each Warrant is exercisable into one Common Share (a “ Warrant Share ”) at an exercise price of C$0.70 per Warrant Share (the “ Exercise Price ”) at any time prior to 5:00 p.m. (Vancouver time) (the “ Warrant Expiry Time ”) on the date that is 24 months following the issuance date thereof (the “ Warrant Expiry Date ”). The Warrants will be governed by a warrant indenture to be entered into on the Closing Date (as defined below) between the Company and Computershare Trust Company of Canada, as warrant agent. The Offered Units will immediately separate into Unit Shares and Warrants upon issuance. See “ Description of Securities Being Distributed – Warrants ”.

The outstanding Common Shares are listed and posted for trading on the Toronto Stock Exchange (the “ TSX ”) under the symbol “ FF ”. The Company has applied to the TSX for approval of the listing of the Unit Shares and Warrant Shares. Listing will be subject to the Company fulfilling all of the listing requirements of the TSX. On August 17, 2020, the last trading day prior to the announcement of the Offering, the closing price per Common Share on the TSX was C$0.53.

Price: C$0.50 per Offered Unit

Per Offered Unit ........................................ Total Offering(3)	Price to Public(4) C$0.50 C$25,000,000	Underwriters’ Commission(1) (4) C$0.03 C$1,500,000	Proceeds to the Company(2) (4)
			C$0.47 C$23,500,000

Notes:

(1) In consideration for the services rendered by the Underwriters in connection with the Offering, the Company has agreed to pay the Underwriters a cash fee (the “ Underwriters’ Commission ”) equal to 6.0% of the gross proceeds of the Offering (including gross proceeds resulting from any exercise of the OverAllotment Option (as defined herein)), other than in respect of sales to certain purchasers, as identified by the Company and as mutually agreed to between the Company and the Underwriters purchasing Offered Units for gross proceeds of up to $1,000,000 (the “ President’s List ”), in respect of which a cash fee equal to 1.0% of the gross proceeds raised from sales to such purchasers will be paid to the Underwriters. See “ Plan of Distribution ”.
(2) After deducting the Underwriters’ Commission but before deducting the expenses of the Offering (estimated to be C$375,000), which will be paid by the Company from the proceeds of the Offering. The Underwriters’ Commission for the Offering will be deducted from the proceeds from the Offering.
(3) The Company has granted to the Underwriters an option (the “ Over-Allotment Option ”), exercisable in whole or in part in the sole discretion of the Underwriters for a period of 30 days from the Closing Date (as defined herein), to purchase up to an additional 7,500,000 units (the “ Over-Allotment Units ”) on the same terms as set forth above solely to cover over-allocations, if any, and for market stabilization purposes. If the Over-Allotment Option is exercised in full, the total “ Price to Public”, “ Underwriters’ Commission” and “ Proceeds to the Company” will be C$28,750,000, C$1,725,000 and C$27,025,000, respectively. The Prospectus also qualifies the grant of the Over-Allotment Option and the distribution of Over-Allotment Units issuable upon exercise of the Over-Allotment Option. A purchaser who acquires Over-Allotment Units forming part of the Underwriters’ over-allocation position acquires those OverAllotment Units under this Prospectus Supplement, regardless of whether the over-allocation position is ultimately filled through the exercise of the OverAllotment Option or secondary market purchases. See “ Plan of Distribution ”.
(4) All figures above assume that no sales are being made to persons on the President’s List.

The following table sets out the maximum number of Over-Allotment Units that may be issued by the Company to the Underwriters pursuant to the Over-Allotment Option granted to the Underwriters:

Underwriters’ Position Over-Allotment Option	Maximum Size Option to purchase up to7,500,000 Units	Exercise Period Up to 30 days from and including the Closing Date	Exercise Price
			C$0.50 per Over-Allotment Unit

Unless the context otherwise requires, all references to the “ Offering ”, “ Offered Units ”, “ Unit Shares ”, “ Warrants ”, and “ Warrant Shares ”, herein includes all securities issuable pursuant to, or in connection with, the exercise of the Over-Allotment Option.

The Underwriters, as principals, conditionally offer the Offered Units, subject to prior sale, if, as and when issued by the Company and accepted by the Underwriters in accordance with the conditions contained in the Underwriting Agreement referred to under “Plan of Distribution” and subject to the approval of certain legal matters on behalf of the Company by Bennett Jones LLP and on behalf of the Underwriters by Wildeboer Dellelce LLP.

In connection with this Offering and subject to applicable laws, the Underwriters may over-allocate or effect transactions to stabilize or maintain the market price of the Common Shares. Such transactions, if commenced, may be discontinued at any time. The Underwriters propose to offer the Offered Units initially at the Offering Price. After the Underwriters have made a reasonable effort to sell all of the Offered Units at the Offering Price, the price at which the Offered Units are distributed pursuant to the Prospectus may be decreased and may be further changed from time to time to an amount not greater than the Offering Price, and the compensation realized by the Underwriters will be decreased by the amount that the aggregate price paid by purchasers for the Offered Units distributed pursuant to the Prospectus is less than the Offering Price. Notwithstanding any reduction by the Underwriters on the Offering Price, the Company will still receive the net proceeds stated above. See “ Plan of Distribution ”.

Subscriptions for the Offered Units will be received subject to rejection or allotment in whole or in part and the right is reserved to close the subscription books at any time without notice. The closing is expected to take place on or about August 26, 2020 or such other date as the Company and the Underwriters may agree (the “ Closing Date ”) but in any event not later than 42 days after the date of this Prospectus Supplement.

It is anticipated that the Unit Shares and Warrants comprising the Offered Units will be delivered under the book-based system through CDS Clearing and Depository Services Inc. (“ CDS ”) or its nominee and deposited in electronic form, or will otherwise be delivered to the Underwriters registered as directed by the Underwriters, on the Closing Date. Except in limited circumstances, a purchaser of Offered Units will receive only a customer confirmation from the registered dealer from or through which the Offered Units are purchased and who is a CDS depository service participant. CDS will record the CDS participants who hold Unit Shares and Warrants on behalf of

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owners who have purchased Offered Units in accordance with the book-based system. No definitive certificates will be issued unless specifically requested or required. See “Plan of Distribution”.

An investment in the Offered Units is speculative and involves a high degree of risk. The risk factors identified in this Prospectus Supplement, the Base Shelf Prospectus and the documents incorporated by reference herein and therein should be carefully reviewed and evaluated by prospective purchasers before purchasing the Offered Units. See “ Risk Factors ” in this Prospectus Supplement, the Base Shelf Prospectus and the documents incorporated by reference herein and therein.

Prospective investors should be aware that the acquisition of Offered Units may have tax consequences in Canada. Such tax consequences for investors may not be described fully herein or in the Base Shelf Prospectus. See “Certain Canadian Federal Income Tax Considerations”. Potential investors are advised to consult their own legal counsel and other professional advisors in order to assess the income tax, legal and other aspects of the Offering in their particular circumstances.

Prospective purchasers should rely only on the information contained in or incorporated by reference in this Prospectus Supplement and the Base Shelf Prospectus. The Company has not authorized any other person to provide prospective purchasers with different information. The Company is not offering the securities in any jurisdiction in which the Offering is not permitted.

Mr. Keith Neumeyer and Mr. Richard Lock are directors of the Company who reside outside of Canada, and each has appointed Bennett Jones LLP at Suite 2500 – 666 Burrard Street, Vancouver, British Columbia V6C 2X8, as his agent for service of process in Canada. Prospective investors are advised that it may not be possible for investors to enforce judgments obtained in Canada against any person or company that is incorporated, continued or otherwise organized under the laws of a foreign jurisdiction or resides outside of Canada, even if the party has appointed an agent for service of process.

The Company’s head office address is Suite 2070 – 1188 West Georgia Street, Vancouver, British Columbia V6E 4A2, and its registered office is located at Suite 2500 – 666 Burrard Street, Vancouver, British Columbia V6C 2X8.

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PROSPECTUS SUPPLEMENT

IMPORTANT NOTICE ABOUT INFORMATION IN THIS PROSPECTUS............................................................ S-5 CAUTIONARY STATEMENTS REGARDING FORWARD-LOOKING INFORMATION ................................... S-5 CAUTIONARY NOTE TO UNITED STATES INVESTORS REGARDING PRESENTATION OF MINERAL RESERVE AND MINERAL RESOURCE ESTIMATES ............................................................................................. S-6 MEANING OF CERTAIN REFERENCES .................................................................................................................... S-7 CURRENCY AND EXCHANGE RATE INFORMATION.......................................................................................... S-8 ELIGIBILITY FOR INVESTMENT ............................................................................................................................... S-8 DOCUMENTS INCORPORATED BY REFERENCE.................................................................................................. S-9 MARKETING MATERIALS......................................................................................................................................... S-10 RISK FACTORS ............................................................................................................................................................. S-13 CONSOLIDATED CAPITALIZATION ....................................................................................................................... S-17 USE OF PROCEEDS ...................................................................................................................................................... S-17 DESCRIPTION OF SECURITIES BEING DISTRIBUTED ...................................................................................... S-18 PLAN OF DISTRIBUTION ........................................................................................................................................... S-19 PRIOR SALES................................................................................................................................................................. S-23 TRADING PRICE AND VOLUME .............................................................................................................................. S-24 CERTAIN CANADIAN FEDERAL INCOME TAX CONSIDERATIONS ............................................................. S-25 LEGAL MATTERS......................................................................................................................................................... S-28 AUDITOR, TRANSFER AGENT AND REGISTRAR ............................................................................................... S-28 STATUTORY AND CONTRACTUAL RIGHTS OF WITHDRAWAL AND RESCISSION ................................ S-28 INTERESTS OF EXPERTS ........................................................................................................................................... S-29 CERTIFICATE OF THE COMPANY.............................................................................................................................C-1 CERTIFICATE OF THE UNDERWRITERS .....................................................................................................................2

BASE SHELF PROSPECTUS

CAUTIONARY STATEMENTS REGARDING FORWARD-LOOKING INFORMATION ...................................... 6 CAUTIONARY NOTE TO US INVESTORS ................................................................................................................... 7 FINANCIAL INFORMATION ........................................................................................................................................... 8 CURRENCY PRESENTATION AND EXCHANGE RATE INFORMATION............................................................. 8 DOCUMENTS INCORPORATED BY REFERENCE..................................................................................................... 8 DOCUMENTS FILED AS PART OF THE REGISTRATION STATEMENT ............................................................ 10 AVAILABLE INFORMATION........................................................................................................................................ 10 SUMMARY OF THE BUSINESS .................................................................................................................................... 11 USE OF PROCEEDS ......................................................................................................................................................... 12 CONSOLIDATED CAPITALIZATION OF THE COMPANY..................................................................................... 12 PLAN OF DISTRIBUTION .............................................................................................................................................. 13 DESCRIPTION OF SECURITIES.................................................................................................................................... 14 PRIOR SALES.................................................................................................................................................................... 17 TRADING PRICE AND VOLUME ................................................................................................................................. 18 CERTAIN FEDERAL INCOME TAX CONSIDERATIONS........................................................................................ 19 RISK FACTORS ................................................................................................................................................................ 19 EXEMPTION FROM NATIONAL INSTRUMENT 44-102 ......................................................................................... 20 LEGAL MATTERS............................................................................................................................................................ 20 INTERESTS OF EXPERTS .............................................................................................................................................. 21 AUDITOR, TRANSFER AGENT AND REGISTRAR .................................................................................................. 22 ENFORCEABILITY OF CERTAIN CIVIL LIABILITIES............................................................................................ 22 CONTRACTUAL RIGHTS OF RESCISSION ............................................................................................................... 22 GLOSSARY OF MINING TERMS.................................................................................................................................. 23 STATUTORY RIGHTS OF WITHDRAWAL AND RESCISSION ............................................................................. 24 CERTIFICATE OF FIRST MINING GOLD CORP. ...................................................................................................... 25

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IMPORTANT NOTICE ABOUT INFORMATION IN THIS PROSPECTUS

This document is in two parts. The first part is this Prospectus Supplement, which describes the terms of the Offering and also adds to and updates information contained in the Base Shelf Prospectus and the documents incorporated by reference therein. The second part, the Base Shelf Prospectus, gives more general information, some of which may not apply to the Offering.

No person is authorized by the Company to provide any information or to make any representation other than as contained in this Prospectus Supplement or the Base Shelf Prospectus in connection with the issue and sale of the Offered Units. Prospective purchasers should rely only on the information contained or incorporated by reference in this Prospectus Supplement and the Base Shelf Prospectus in connection with the purchase of the Offered Units. Information in this Prospectus Supplement updates and modifies the information in the Base Shelf Prospectus and information incorporated by reference therein. Prospective purchasers should assume that the information appearing in this Prospectus Supplement and the Base Shelf Prospectus is accurate only as of the date on the front of such documents and that information contained in any document incorporated by reference is accurate only as of the date of that document unless specified otherwise. The Company’s business, financial condition, financial performance and prospects may have changed since those dates.

The address of the Company’s website is www.firstmininggold.com. Information contained on the Company’s website does not form part of this Prospectus Supplement or the Base Shelf Prospectus nor is it incorporated by reference herein or therein. Prospective purchasers should rely only on information contained or incorporated by reference in this Prospectus Supplement and the Base Shelf Prospectus.

Market data and certain industry forecasts used in this Prospectus Supplement, the Base Shelf Prospectus and the documents incorporated by reference herein or therein were obtained from market research, publicly available information and industry publications. The Company believes that these sources are generally reliable, but the accuracy and completeness of the information is not guaranteed. The Company has not independently verified this information and does not make any representation as to the accuracy of this information.

The Company’s annual consolidated financial statements that are incorporated by reference into this Prospectus Supplement and the Base Shelf Prospectus have been prepared in accordance with International Financial Reporting Standards as issued by the International Accounting Standards Board.

CAUTIONARY STATEMENTS REGARDING FORWARD-LOOKING INFORMATION

Certain statements contained in this Prospectus Supplement, the Base Shelf Prospectus and the documents incorporated by reference herein and therein constitute forward-looking information or forward-looking statements under applicable securities laws (collectively, “ forward-looking statements ”). These statements relate to future events or future performance, business prospects or opportunities of the Company that are based on forecasts of future results, estimates of amounts not yet determined and assumptions of management made in light of management’s experience and perception of historical trends, current conditions and expected future developments. All statements other than statements of historical fact may be forward-looking statements. Any statements that express or involve discussions with respect to predictions, expectations, beliefs, plans, projections, objectives, assumptions or future events or performance (often, but not always, using words or phrases such as “seek”, “anticipate”, “plan”, “continue”, “estimate”, “expect”, “may”, “will”, “project”, “predict”, “forecast”, “potential”, “targeting”, “intend”, “could”, “might”, “should”, “believe” and similar expressions) are not statements of historical fact and may be “forward-looking statements”.

Examples of forward-looking statements in this Prospectus Supplement, the Base Shelf Prospectus and the documents incorporated by reference herein and therein include, but are not limited to statements in respect of: sales of Offered Units; the use of net proceeds of the Offering; the Company’s intention to complete the Offering on the terms and conditions described herein; the listing of the Unit Shares on the TSX; the anticipated effect of the Offering on the performance of the Company; future acquisitions of mineral properties; the Company’s strategy of de-risking material assets through exploration, drilling, calculating resource estimates, conducting economic studies and other activities; statements relating to the Company’s vision and strategy; the Company’s intention to utilize its management team’s expertise to successfully permit and construct producing mines at its material assets; statements relating to the criteria the Company will use when assessing potential acquisitions; the Company’s belief that it will continue to be able to locate and retain professionals with the necessary specialized skills and knowledge; statements regarding the Company’s intention and ability to select, acquire and bring to production suitable properties or prospects for mineral exploration and production; the Company’s ability to raise the capital necessary to fund its operations and the potential development of its properties; the Company’s ability to obtain the resources to conduct exploration and development activities on its properties; the Company’s belief that the policies and procedures implemented by the executive management team of the Company provide a safe working environment for all of its employees, consultants, contractors and stakeholders; statements regarding shifts in gold demand; the Company’s intention to continue to make expenditures to ensure

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compliance with applicable laws and regulations; the Company’s ability to work with the various Indigenous communities in relation to the development of the Company’s projects; the Company’s intentions and expectations regarding exploration at any of its mineral properties; forecasts relating to mining, development and other activities at the Company’s operations; statements regarding potential increases in the ultimate recovery of gold and silver from its properties, including the Springpole Gold Project; forecasts relating to market developments and trends in global supply and demand for gold; future royalty and tax payments and rates; future work on the Company’s non-material properties; the Company’s intention to complete a Pre-Feasibility Study for the Springpole Gold Project; the Company’s intention to advance the permitting process at the Springpole Gold Project, including the proposed submission of an environmental impact statement and the timing of such submission; and the Company’s mineral reserve and mineral resource estimates.

Forward-looking statements involve known and unknown risks, uncertainties and other factors that may cause actual results or events to differ materially from those anticipated in such forward-looking statements. Prospective investors are cautioned that any such statements are not guarantees of future performance and those actual results or developments may differ materially from those projected in the forward-looking statements. These forward-looking statements involve risks and uncertainties relating to, among others: the potential impact of the COVID-19 pandemic on the business, operations and financial condition of the Company; exploration, development and production risks; operational hazards; global financial conditions; commodity price fluctuations; availability of capital and financing on acceptable terms; the Company’s lack of history of commercially producing metals from mineral exploration properties; the Company’s mineral reserve and resource estimates may not be reliable, or the Company may encounter unexpected or challenging geological, hydrological or mining conditions; the Company’s exploration plans may be delayed or may not succeed; the Company may not be able to obtain or maintain necessary permits or approvals from government authorities; the Company may be affected by environmental, safety and regulatory risks, including increased regulatory burdens or delays; there may be defects in, or challenges to, title to the Company’s properties; the Company may lose its interest in certain projects if it fails to make certain required payments or minimum expenditures; the Company may be unable to enforce its legal rights under its existing agreements, permits or licences, or may be subject to litigation or arbitration that has an adverse outcome; accidents or equipment breakdowns may occur; cyclical nature of the mining industry; there may be changes to government regulations or policies, including tax and trade laws and policies; the Company may be adversely affected by changes in foreign currency exchange rates, interest rates or tax rates; the Company’s estimates of production, purchases, costs, decommissioning or reclamation expenses, or their tax expense estimates, may prove to be inaccurate; natural phenomena, including inclement weather, fire, flood and earthquakes may occur and impact the Company’s operations; the Company’s operations may be disrupted due to problems with its own or customer facilities, the unavailability of reagents or equipment, equipment failure, lack of tailings capacity, labour shortages, ground movements, transportation disruptions or accidents or other exploration and development risk; future sales by existing shareholders could reduce the market price of the Common Shares; volatility in securities markets and volatility in mineral prices; the Company’s broad discretion relating to the use of proceeds raised hereunder; the absence of a market through which the Company’s securities, other than the Common Shares, may be sold, and additional factors described under the heading “ Risk Factors ” in this Prospectus Supplement and the Base Shelf Prospectus, under the heading “ Risks That Can Affect Our Business ” in the Company’s annual information form for the year ended December 31, 2019 and under the section “ Risks and Uncertainties ” in the Company’s management discussion and analysis for the year ended December 31, 2019.

The Company believes that the expectations reflected in any forward-looking statements are reasonable, but no assurance can be given that these expectations will prove to be correct and such forward-looking statements included in, or incorporated by reference into, this Prospectus Supplement of the Prospectus should not be unduly relied upon. These statements speak only as of the date of this Prospectus Supplement of the Prospectus, as applicable. The Company does not intend, and does not assume any obligation, to update these forwardlooking statements, except as required by applicable laws. Actual results may differ materially from those expressed or implied by such forward-looking statements.

CAUTIONARY NOTE TO UNITED STATES INVESTORS REGARDING PRESENTATION OF MINERAL RESERVE AND MINERAL RESOURCE ESTIMATES

This Prospectus Supplement and the Base Shelf Prospectus, including the documents incorporated by reference herein and therein, have been prepared in accordance with the requirements of the securities laws in effect in Canada, which differ from the requirements of United States securities laws. All mining terms used herein but not otherwise defined have the meanings set forth in National Instrument 43-101 Standards of Disclosure for Mineral Projects (“ NI 43-101 ”). The definitions of Proven and Probable Mineral Reserves (“ Mineral Reserves ” or “ Reserves ”) used in NI 43-101 differ from the definitions in the SEC Industry Guide 7. Under SEC Industry Guide 7 standards, a “final” or “bankable” feasibility study is required to report reserves, the three-year history average price is used in any reserve or cash flow analysis to designate reserves and the primary environmental analysis or report must be filed with the appropriate governmental authority.

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In addition, the terms “Mineral Resource”, “Measured Mineral Resource”, “Indicated Mineral Resource” and “Inferred Mineral Resource” are defined in and required to be disclosed by NI 43-101; however, these terms are not defined terms under SEC Industry Guide 7 and normally are not permitted to be used in reports and registration statements filed with the SEC. Investors are cautioned not to assume that any part or all of the mineral deposits in these categories will ever be converted into reserves. “Inferred Mineral Resources” have a great amount of uncertainty as to their existence, and great uncertainty as to their economic and legal feasibility. It cannot be assumed that all or any part of an Inferred Mineral Resource will ever be upgraded to a higher category. Under Canadian securities laws, estimates of Inferred Mineral Resources may not form the basis of feasibility or prefeasibility studies, except in certain specific cases. Additionally, disclosure of “contained ounces” in a resource is permitted disclosure under Canadian securities laws, however the SEC normally only permits issuers to report mineralization that does not constitute “reserves” by SEC standards as in place tonnage and grade without reference to unit measurements.

Accordingly, information contained in this Prospectus Supplement and the Base Shelf Prospectus and the documents incorporated by reference herein and therein containing descriptions of the Company’s mineral deposits may not be comparable to similar information made public by U.S. companies subject to the reporting and disclosure requirements of United States federal securities laws and the rules and regulations thereunder.

See “ National Instrument 43-101 Definitions ” in the Annual Information Form, which is incorporated by reference herein, for a description of certain of the mining terms used in this Prospectus Supplement, the Base Shelf Prospectus and the documents incorporated by reference herein and therein.

MEANING OF CERTAIN REFERENCES

For simplicity, the Company uses terms in this Prospectus Supplement to refer to the investments and operations of the Company and its direct and indirect subsidiaries as a whole. Accordingly, in this Prospectus Supplement, unless the context otherwise requires, the “Company” is referring to First Mining Gold Corp. and its direct and indirect subsidiaries.

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CURRENCY AND EXCHANGE RATE INFORMATION

In this Prospectus Supplement, all dollar amounts referenced, unless otherwise indicated, are expressed in Canadian dollars and are referred to as “$” or “C$”. United States dollars are referred to as “US$”. The high, low and closing exchange rates for United States dollars in terms of the Canadian dollar for each of the indicated periods, as quoted by the Bank of Canada, were as follows:

High……………………………………………………………….. Low……………………………………………………………….. Rate at end of period...…………………………………………….	Year Ended December 31, 2019 (US$)
	US$0.7699 US$0.7353 US$0.7699

On August 18, 2020, the exchange rate for United States dollars in terms of the Canadian dollar, as quoted by the Bank of Canada, was C$1.00 = US$0.7593.

ELIGIBILITY FOR INVESTMENT

In the opinion of Bennett Jones LLP, counsel to the Company, and Wildeboer Dellelce LLP, counsel to the Underwriters, based on the current provisions of the Income Tax Act (Canada) and the regulations thereunder (collectively, the “ Tax Act ”), in force as of the date hereof, the Unit Shares, Warrants, and Warrant Shares issuable upon the exercise of the Warrants, if issued on the date hereof, would be “qualified investments” (as defined in the Tax Act) for trusts governed by a registered retirement savings plan, registered retirement income fund, registered education savings plan, registered disability savings plan, tax-free savings account (collectively referred to as “ Registered Plans ”) or a deferred profit sharing plan (“ DPSP ”), provided that at such time:

(i) in the case of Unit Shares and Warrant Shares, the Unit Shares or Warrant Shares, as applicable, are listed on a “designated stock exchange” as defined in the Tax Act (which currently includes the TSX) or the Company qualifies as “public corporation” (as defined in the Tax Act); and
(ii) in the case of the Warrants, the Warrant Shares are qualified investments as described in (i) above and neither the Company, nor any person with whom the Company does not deal at arm’s length, is an annuitant, a beneficiary, an employer or a subscriber under or a holder of such Registered Plan or DPSP.

Notwithstanding the foregoing, the holder of, the annuitant under or the subscriber of a Registered Plan (the “ Controlling Individual will be subject to a penalty tax in respect of Unit Shares, Warrant Shares or Warrants held in the Registered Plan if such securities are a “prohibited investment” (as defined in the Tax Act) for the particular Registered Plan. The Unit Shares, Warrant Shares or Warrants generally will not be a “prohibited investment” for a particular Registered Plan unless (i) the Controlling Individual does not deal at arm’s length with the Company for the purposes of the Tax Act, or (ii) the Controlling Individual has a “significant interest” (as defined in subsection 207.01(4) of the Tax Act) in the Company. In addition, the Unit Shares and Warrant Shares will generally not be a “prohibited investment” if such securities are “excluded property” (as defined in the Tax Act) for the particular Registered Plan.

Persons who intend to hold Unit Shares, Warrants or Warrant Shares in a trust governed by a Registered plan should consult their own tax advisors with respect to the application of theses rules in their particular circumstances.

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DOCUMENTS INCORPORATED BY REFERENCE

This Prospectus Supplement is deemed to be incorporated by reference in the Prospectus solely for the purpose of the Offering. Other documents are also incorporated or deemed to be incorporated by reference in the Prospectus and reference should be made to the Prospectus for full particulars thereof.

Information has been incorporated by reference in this Prospectus Supplement and the Base Shelf Prospectus from documents filed with securities commissions or similar authorities in each of the provinces of Canada (other than Québec) (the “ Qualifying Jurisdictions ”). Copies of the documents incorporated herein by reference or a copy of the Company’s permanent information record may be obtained on request without charge from the Company’s General Counsel & Corporate Secretary at Suite 2070 – 1188 West Georgia Street, Vancouver, British Columbia V6E 4A2, or by accessing the disclosure documents available electronically in Canada on the System for Electronic Document Analysis and Retrieval (“ SEDAR ”), which can be accessed at www.sedar.com. The filings of the Company through SEDAR are not incorporated by reference in this Prospectus Supplement or the Base Shelf Prospectus except as specifically set out herein.

As at the date hereof, the following documents of the Company, filed with the securities commissions or similar authorities in the Qualifying Jurisdictions, are specifically incorporated by reference into and form an integral part of this Prospectus Supplement, provided that such documents are not incorporated by reference to the extent that their contents are modified or superseded by a statement contained in this Prospectus Supplement, the Base Shelf Prospectus or in any other subsequently filed document that is also incorporated by reference in this Prospectus Supplement, as further described below:

(a) the annual information form of the Company dated March 30, 2020 for the financial year ended December 31, 2019, filed on SEDAR on March 30, 2020 (the “ Annual Information Form ”);
(b) the audited consolidated financial statements of the Company as at and for the years ended December 31, 2019 and December 31, 2018, together with the notes thereto and the independent auditor’s report thereon, filed on SEDAR on March 30, 2020;
(c) the management’s discussion and analysis of the Company for the financial year ended December 31, 2019, filed on SEDAR on March 30, 2020;
(d) the unaudited condensed interim consolidated financial statements of the Company as at and for the three and six months ended June 30, 2020 and June 30, 2019, together with the notes thereto, filed on SEDAR on August 4, 2020 (the “ Interim Financial Statements ”);
(e) the management’s discussion and analysis of the Company for the three and six months ended June 30, 2020, filed on SEDAR on August 4, 2020 (the “ Interim MD&A ”);
(f) the management information circular of the Company dated May 6, 2020 distributed in connection with the Company’s annual general meeting of shareholders held on June 16, 2020, filed on SEDAR on May 8, 2020;
(g) the material change report of the Company dated August 11, 2020 in connection with the completion of the previously announced transaction with Treasury Metals Inc. (“ Treasury Metals ”) pursuant to which the Company sold to Treasury Metals all of the issued and outstanding shares of Tamaka Gold Corporation (“ Tamaka ”), a previously wholly-owned subsidiary of the Company that owns the Goldlund Gold Project (“ Goldlund ”), filed on SEDAR on August 11, 2020 (the “ Treasury Metals Transaction ”);
(h) the material change report of the Company dated June 19, 2020 in connection with the Company entering into a definitive agreement (the “ Silver Purchase Agreement ”) with First Majestic Silver Corp. (“ First Majestic ”), filed on SEDAR on June 19, 2020;
(i) the material change report of the Company dated June 12, 2020 in connection with the Company entering into a definitive share purchase agreement (the “ Treasury Metals Agreement ”) with Treasury Metals in respect of the Treasury Metals Transaction, filed on SEDAR on June 12, 2020;
(j) the material change report of the Company dated March 23, 2020 in connection with the Company entering into a definitive earn-in agreement (the “ Earn-In Agreement ”) with Auteco Minerals Ltd. (“ Auteco ”), filed on SEDAR on March 23, 2020;

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(k) the material change report of the Company dated February 6, 2020 in connection with the Company entering into a binding term sheet with Auteco in respect of the Earn-In Agreement, filed on SEDAR on February 6, 2020;
(l) the business acquisition report of the Company dated August 17, 2020 in connection with the Treasury Metals Transaction, filed on SEDAR on August 17, 2020;
(m) the Marketing Materials (as defined below); and
(n) the Amended Marketing Materials (as defined below).

Any statement contained in this Prospectus Supplement, the Base Shelf Prospectus or in a document incorporated or deemed to be incorporated by reference herein or therein shall be deemed to be modified or superseded, for purposes of this Prospectus Supplement and the Base Shelf Prospectus, to the extent that a statement contained herein or therein or in any other subsequently filed document that also is or is deemed to be incorporated by reference in this Prospectus Supplement or the Base Shelf Prospectus modifies or supersedes that statement. Any such modifying or superseding statement need not state that it has modified or superseded a prior statement or include any other information set forth in the document that it modifies or supersedes. The making of a modifying or superseding statement shall not be deemed an admission for any purposes that the modified or superseded statement, when made, constituted a misrepresentation, an untrue statement of a material fact or an omission to state a material fact that is required to be stated or that is necessary to make a statement not misleading in light of the circumstances in which it was made. Any statement so modified or superseded shall not be considered in its unmodified or superseded form to constitute part of this Prospectus Supplement or the Base Shelf Prospectus; rather only such statement as so modified or superseded shall be considered to constitute part of this Prospectus Supplement and the Prospectus.

The Company has not provided or otherwise authorized any other person to provide the prospective purchasers with information other than as contained or incorporated by reference in this Prospectus Supplement or the Base Shelf Prospectus. If prospective purchasers are provided with different or inconsistent information, they should not rely on it.

MARKETING MATERIALS

Any “marketing materials” (as defined in National Instrument 41-101 General Prospectus Requirements (“ NI 41-101 ”)) are not part of this Prospectus Supplement or the Base Shelf Prospectus to the extent that the contents thereof have been modified or superseded by a statement contained in this Prospectus Supplement or any amendment. Any “template version” of “marketing materials” (as defined in NI 41-101) filed with the securities commission or similar authority in each of the provinces of Canada, except Québec, in connection with the Offering after the date hereof but prior to the termination of the distribution of the Offered Units under this Prospectus Supplement (including any amendments to, or an amended version of, any template version of marketing materials) is deemed to be incorporated by reference into this Prospectus Supplement and in the Base Shelf Prospectus.

The term sheet for the Offering dated August 17, 2020 (the “ Marketing Materials ”) was filed under the Company’s profile on SEDAR at www.sedar.com. The Marketing Materials have been modified to reflect the increase in the Offering from 40,000,000 Units for gross proceeds of $20,000,000 to 50,000,000 Units for gross proceeds of $25,000,000. The Company has prepared and filed a revised term sheet for the Offering dated August 18, 2020 (the “ Amended Marketing Materials ”) which can be viewed under the Company’s profile on SEDAR at www.sedar.com.

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SUMMARY OF THE BUSINESS

First Mining is a Canadian gold developer focused on the development and permitting of the Springpole Gold Project in northwestern Ontario. The Springpole Gold Project is one of the largest undeveloped gold projects in Canada, hosting a mineral resource base of 4.67 million ounces of gold in the Indicated category and 0.23 million ounces of gold in the Inferred category (as at July 31, 2020). A prefeasibility study is underway at the Springpole Gold Project (the “ Springpole Pre-Feasibility Study ”), with completion targeted in early 2021, and permitting is ongoing with submission of an environmental impact statement also targeted for 2021. The Company recently completed the Treasury Metals Transaction for the indirect sale of Goldlund, pursuant to which the Company now holds an equity position, as of the date hereof, of approximately 39% in Treasury Metals, on a non-diluted basis. First Mining’s Canadian property portfolio also includes the Pickle Crow (being advanced in partnership with Auteco), Cameron, Hope Brook, Duparquet, Duquesne, and Pitt gold projects.

The mineral resource numbers stated above with respect to the property located at the Springpole Gold Project (the “ Springpole Property ”) are derived from the independent technical report titled “Preliminary Economic Assessment Update for the Springpole Gold Project, Ontario, Canada” (the “ Springpole PEA ”), dated November 5, 2019, which was prepared by SRK Consulting (Canada) Inc. and is available at www.sedar.com under the Company’s SEDAR profile. Readers are cautioned that the Springpole PEA is preliminary in nature, it includes Inferred Mineral Resources that are considered too speculative geologically to have the economic considerations applied to them that would enable them to be categorized as mineral reserves, and there is no certainty that the preliminary economic assessment in the Springpole PEA will be realized.

Recent Developments

On August 11, 2020, the Company announced that Auteco had notified the Company that it had fulfilled the initial $750,000 exploration expenditures requirement under the Earn-In Agreement on the Pickle Crow Gold Project located in Northern Ontario, regarding the first portion of Auteco’s stage 1 earn-in requirements. In order to complete the remaining requirements of the stage 1 earn-in and thereby earn a 51% interest in PC Gold Inc., the Company’s wholly-owned subsidiary that owns Pickle Crow, Auteco will need to incur a further $4.25 million in expenditures relating to Pickle Crow within the next two years, and Auteco will need to issue a further 100 million shares to the Company on or before the date these expenditures have been completed.

On July 2, 2020, the Company announced the closing of its previously announced transaction with First Majestic to advance the Company’s wholly-owned Springpole Gold Project. Under the terms of the Silver Purchase Agreement, First Majestic agreed to pay First Mining total consideration of US$22.5 million in a combination of cash and shares of First Majestic, over three stages, for the right to purchase 50% of the payable silver produced from the Springpole Gold Project for the life of the project. As part of the transaction with First Majestic, the Company issued 30,000,000 Common Share purchase warrants to First Majestic on July 2, 2020. Each warrant entitles First Majestic to purchase one Common Share at an exercise price of $0.40 for a period of five years.

Treasury Metals

On August 7, 2020, the Company announced the closing of the Treasury Metals Transaction pursuant to which Treasury Metals acquired all of the issued and outstanding shares of Tamaka in exchange for (a) the issuance to the Company of 130,000,000 common shares of Treasury Metals (“ TML Shares ”) and 35,000,000 warrants to acquire TML Shares (“ TML Warrants ”) (both on a pre-consolidation basis); (b) the grant to the Company of a 1.5% net smelter returns royalty on all Goldlund claims; and (c) payment of $5,000,000 in the aggregate payable upon completion of certain milestones at Goldlund. Following closing of the Treasury Metals Transaction, Treasury Metals completed a 3 to 1 consolidation of TML Shares and, as a result, the TML Warrants and TML Shares issued to the Company under the Treasury Metals Transaction were adjusted, with the Company now holding 43,333,333 TML Shares and 11,666,666 TML Warrants on a post-consolidation basis. The Company currently holds an ownership interest in Treasury Metals of approximately 39% of the TML Shares outstanding on a non-diluted basis.

Treasury Metals is a Canadian mineral exploration and development company, the common shares of which are listed on the TSX under the trading symbol “TML” and on the OTCQX, currently under the symbol “TSRMD” (reverting to “TSRMF” on September 11, 2020). Treasury Metals’ flagship asset is its 100% owned Goliath Gold Project, an advanced stage, high-grade gold deposit near Dryden,

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Ontario, which is adjacent to the Goldlund Gold Project that Treasury Metals acquired from the Company pursuant to the Treasury Metals Transaction.

Treasury Metals has announced that it has initiated a number of work programs intended to advance both the Goliath and Goldlund gold projects. These activities include:

Completion of an economic evaluation of a Goliath plus Goldlund scenario. Technical studies are underway to support this analysis, including plant and processing facilities, mining optimization, and an evaluation of potential operations at Goliath (underground and open pit) combined with Goldlund open pit mining scenarios.
The commencement of a 25,000-metre drill program.
Environmental baseline collection commenced to assist with the development and permitting activities for Goldlund.

The following information with respect to the Goliath Gold Project is derived from, and in some instances is a direct extract from, the technical report entitled “ The Amended Updated Mineral Resource Estimate for the Goliath Gold Project, Kenora Mining Division, Northwestern Ontario for Treasury Metals Inc.” dated August 13, 2020 (effective date of July 1, 2019) (the “ Goliath Technical Report ”), which has been filed by Treasury Metals under its profile on SEDAR at www.sedar.com.

			Mineral Resource Estimates(1-10)	Mineral Resource Estimates(1-10)	Mineral Resource Estimates(1-10)	Mineral Resource Estimates(1-10)
Area	Classification	Cut-off AuEq (g/t)	Tonnes (kt)	Au (g/t)	Contained Au(koz)	Ag (g/t)	Contained Au(koz)	AuEq (g/t)	Contained AuEq (koz)
Pit Constrained	Measured	0.4	762	1.91	47	8.86	217	1.99	49
	Indicated	0.4	11,849	1.37	522	5.47	2,083	1.42	541
	Meas+Ind Inferred	0.4 0.4	12,611 595	1.40 1.05	569 20	5.67 2.63	2,300 50	1.45 1.08	590 21
Underground (“UG”)	Measured Indicated	1.9 1.9	163 3,429	6.42 5.34	34 589	25.81 16.64	135 1,834	6.65 5.49	35 605
	Meas+Ind Inferred	1.9 1.9	3,591 1,414	5.39 4.43	623 201	17.05 11.42	1,969 519	5.54 4.53	640 206
Total	Measured	0.4+1.9	925	2.70	80	11.84	352	2.81	83
	Indicated	0.4+1.9	15,277	2.26	1,111	7.98	3,917	2.33	1,146
	Meas+Ind	0.4+1.9	16,202	2.29	1,192	8.20	4,269	2.36	1,230
	Inferred	0.4+1.9	2,009	3.43	222	8.81	569	3.51	227

Notes:

(1) Mineral Resources, which are not Mineral Reserves, do not have demonstrated economic viability.

(2) The estimate of Mineral Resources may be materially affected by environmental, permitting, legal, title, taxation, socio-political, marketing, or other relevant issues.

(3) The Inferred Mineral Resource in this estimate has a lower level of confidence than that applied to an Indicated Mineral Resource and must not be converted to a Mineral Reserve.

(4) The Mineral Resources in this table were estimated using the Canadian Institute of Mining, Metallurgy and Petroleum (“ CIM ”), CIM Standards on Mineral Resources and Reserves, Definitions and Guidelines prepared by the CIM Standing Committee on Reserve Definitions and adopted by the CIM Council.

(5) The mined tonnage by historical underground drifts was not removed as the amount was insignificant to this Mineral Resource Estimate.

(6) A gold price of US$1,275/oz and silver price of US$16.50/oz based on the June 30, 2019 three-year trailing average prices and an exchange rate of US$1.00=Cdn0.77 were utilized in the AuEq cut-off grade calculations of 0.40 g/t AuEq for open pit and 1.90 g/t AuEq for UG Mineral Resources.

(7) Open pit mining costs were assumed at C$3.45/t for mineralized material, C$3.30/t for waste rock and C$2.00/t for overburden, while UG mining costs were assumed at C$77.00/t, with process costs of C$18.15/t, G&A of C$2.86/t, and process recoveries of 95.5% for gold and 62.6% for silver. (8) The Au:Ag ratio used for AuEq was 112.17.

(9) A bulk density model averaged 2.78 t/m[3] for mineralized material.

(10) Totals in the table may not sum due to rounding.

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The Goliath Technical Report is not incorporated by reference in this Prospectus Supplement or the Base Shelf Prospectus.

The following information with respect to the Goldlund Gold Project is derived from, and in some instances is a direct extract from, the technical report entitled “ Technical Report Re-Issue, Goldlund Gold Project, Sioux Lookout, Ontario ” dated July 28, 2020 (effective date of July 22, 2020) (the “ Goldlund Technical Report ”), which has been filed by Treasury Metals under its profile on SEDAR at www.sedar.com.

Classification	Zone	Tonnage	Au g/t	Ounces
Measured	1	-	-	-
	2	-	-	-
	3	-	-	-
	4	-	-	-
	5	-	-	-
	7	-	-	-
	8	-	-	-
	Subtotal	-	-	-
Indicated	1	4,882,400	2.16	330,150
	2	1,642,900	1.76	93,000
	3	-	-	-
	4	1,664,600	2.73	146,100
	5	-	-	-
	7	4,161,600	1.58	210,753
	8	508,600	2.00	29,200
	Subtotal	12,860,000	1.96	809,200
M&I		12,860,000	1.96	809,200
Inferred	1	11,288,000	1.54	558,600
	2	1,028,000	1.22	40,000
	3	1,385,000	1.61	71,666
	4	734,000	2.40	57,000
	5	1,284,000	1.19	49,000
	7	1,928,000	1.29	79,688
	8	715,000	0.90	21,000
	Subtotal	18,362,000	1.49	876,954

Notes:

(1) The overall stripping ratio for the Whittle pit is 4.71:1.

(2) A base case cut-off grade of 0.4 g/t Au was used for both the initial 2017 mineral resource estimate and the updated 2019 mineral resource estimate.

(3) Resources are stated as contained within a potentially economic limiting pit shell using a metal price of US$1,350 per ounce of gold, mining costs of US$2.00 per tonne, processing plus G&A costs of US$15.40 per tonne, 93% recoveries and an average pit slope of 48 degrees.

(4) Mineral resources are not mineral reserves and do not have demonstrated economic viability. There is no certainty that all or any part of the mineral resources will be converted into mineral reserves.

(5) Mineral resource tonnage and contained metal have been rounded to reflect the accuracy of the estimate, and numbers may not add due to rounding.

The Goldlund Technical Report is not incorporated by reference in this Prospectus Supplement or the Base Shelf Prospectus.

RISK FACTORS

Investing in the Offered Units involves a high degree of risk. The Offered Units should be considered a speculative investment due to the high-risk nature of the Company’s business. In addition to the other information contained in this Prospectus Supplement, the Base

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Shelf Prospectus and the documents incorporated by reference herein and therein, prospective purchasers should carefully consider the risks described under the “Risk Factors” section of this Prospectus Supplement, the Base Shelf Prospectus and the documents incorporated herein and therein by reference before purchasing any Offered Units. If any such risks actually occur, the Company’s business, financial condition, financial performance and prospects could materially suffer. As a result, the trading price of the Company’s securities, including the Common Shares, could decline, and purchasers might lose all or part of their investment. The risks set out in this Prospectus Supplement and the Base Shelf Prospectus are not the only risks that the Company faces; risks and uncertainties not currently known to it or that it currently deems to be immaterial may also materially and adversely affect its business, financial condition, financial performance and prospects. Prospective purchasers should also refer to the other information set forth or incorporated by reference in this Prospectus Supplement and the Base Shelf Prospectus, including under the heading “Risks That Can Affect Our Business” in the Annual Information Form.

Global Financial Conditions

Global financial conditions have, at various times in the past and may, in the future, experience extreme volatility. Many industries, including the mining industry, are impacted by volatile market conditions. Global financial conditions may be subject to sudden and rapid destabilizations in response to economic shocks or other events, such as developments concerning the novel coronavirus COVID19 pandemic. A slowdown in the financial markets or other economic conditions, including but not limited to consumer spending, employment rates, business conditions, inflation, fluctuations in fuel and energy costs, consumer debt levels, lack of available credit, the state of the financial markets, interest rates and tax rates, may adversely affect the Company’s growth and financial condition. Future economic shocks may be precipitated by a number of causes, including government debt levels, fluctuations in the price of oil and other commodities, volatility of metal prices, geopolitical instability, changes in laws or governments, war, terrorism, the volatility of currency exchange rates inflation or deflation, the devaluation and volatility of global stock markets, pandemics and natural disasters. Any sudden or rapid destabilization of global economic conditions could impact the Company’s ability to obtain equity or debt financing in the future on terms favourable to the Company or at all. In such an event, the Company’s operations and financial condition could be adversely impacted.

Public Health Crises

The Company’s business, operations and financial condition could be materially adversely affected by the outbreak of epidemics, pandemics or other health crises, such as COVID-19, and by reactions by government and private actors to such outbreaks. As at the date of this Prospectus Supplement, the global reactions to the spread of COVID-19 have led to, among other things, significant restrictions on travel, quarantines, temporary business closures and a general reduction in consumer activity. While these effects are expected to be temporary, the duration of the disruptions to business internationally and the related financial impact cannot be estimated with any degree of certainty at this time. Such public health crises can result in disruptions and extreme volatility in financial markets and global supply chains as well as declining trade and market sentiment and reduced mobility of people, all of which could impact commodity prices, interest rates, credit ratings, credit risk, availability of financing and inflation. The risks to the Company of such public health crises also include risks to employee health and safety and may result in a slowdown or temporary suspension of operations at some or all of the Company’s mineral properties as well as its head office. Although the Company has the capacity to continue certain administrative functions remotely, many other functions, including the conduct of exploration and development programs, cannot be conducted remotely and may be impacted or delayed if the Company experiences limitations on employee mobility.

On March 24, 2020, the province of Ontario implemented an emergency order (the “ Emergency Order ”) mandating the closure of all non-essential workplaces in the province. The Emergency Order has since been extended and remains in effect, although most parts of the province are in varying stages of re-opening, and the Company’s property located at the Springpole Property and its other exploration properties in Ontario are at present not directly affected by the Emergency Order. However, there can be no guarantee that the re-opening process will not be reversed in the future or that governments in other provinces in which the Company has mineral properties will not pass orders reducing or preventing access to the Company’s properties. Any such orders may have a material adverse effect upon ongoing exploration programs at the Company’s properties and, ultimately, on the Company’s business and financial condition. At this point, the extent to which the COVID-19 pandemic may impact the Company remains uncertain; however, it is possible that the COVID19 pandemic, or other epidemics, pandemics or other health crises, could have a material adverse effect on the Company’s business, results of operations and financial condition.

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As discussed in the Interim MD&A under “2020 Highlights”, the Company had temporarily demobilized the contractors and staff at its Springpole Gold Project for a period of time. Although development activities have recommenced at the Springpole Gold Project, there can be no assurance that the Company will not be required to demobilize its personnel and contractors again in the future. Any additional demobilization may have an adverse impact on the Company’s ability to conduct exploration and further advance its work programs on the affected properties.

Risks Relating to the Treasury Metals Transaction

The Treasury Metals Agreement contains customary representations, warranties and indemnities from the Company relating to Tamaka and the Goldlund property. A misrepresentation thereunder or breach by the Company of any of the other terms or conditions of the Treasury Metals Agreement could lead to potential liability, which may have a material adverse impact on the Company’s financial performance, cash flow and results of operations.

As a result of the Treasury Metals Transaction, the Company now owns 43,333,333 TML Shares, representing approximately 39% of the issued and outstanding TML Shares, on a non-diluted basis, as of the date of this Prospectus Supplement. Although the Company has certain rights pursuant to an investor rights agreement entered into in connection with the Treasury Metals Transaction and has the right to appoint three of the seven directors of Treasury Metals, the Company does not directly control the management of Treasury Metals and Treasury Metals has its own management. Treasury Metals’ business is itself subject to the operational and business risks inherent to a gold exploration and development company and to that extent, Treasury Metals’ business will be subject to many of the same business risks applicable to the Company and which are set out elsewhere in this Prospectus Supplement and in the Base Shelf Prospectus. In the event that any such risks materialize there may be a material adverse impact upon Treasury Metals and the market price of its shares which, in turn, may have a material adverse impact on the Company.

No Assurance of Active or Liquid Market

No assurance can be given that an active or liquid trading market for the Common Shares will be sustained. If an active or liquid market for the Common Shares fails to be sustained, the prices at which such shares trade may be adversely affected. Whether or not the Common Shares will trade at lower prices depends on many factors, including the liquidity of the Common Shares, prevailing interest rates and the markets for similar securities, general economic conditions and the Company’s financial condition, historic financial performance and future prospects.

If the Unit Shares are traded after their initial issue, they may trade at prices lower than their initial offering prices depending on the market and other factors including general economic conditions and the Company’s financial condition. There can be no assurance as to the liquidity of the trading market for the Common Shares.

Public Markets and Share Prices

The market price of the Unit Shares that become listed and posted for trading on the TSX or any other stock exchange could be subject to significant fluctuations in response to variations in the Company’s financial results or other factors. In addition, fluctuations in the stock market may adversely affect the market price of the Unit Shares that become listed and posted for trading on a stock exchange regardless of the financial performance of the Company. Securities markets have also experienced significant price and volume fluctuations from time to time. In some instances, these fluctuations have been unrelated or disproportionate to the financial performance of issuers. Market fluctuations may adversely impact the market price of the Unit Shares that become listed and posted for trading on a stock exchange. There can be no assurance of the price at which the Unit Shares that become listed and posted for trading on a stock exchange will trade.

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Additional Issuances and Dilution

The Company may issue and sell additional securities of the Company from time to time. The Company cannot predict the size of future issuances of securities of the Company or the effect, if any, that future issuances and sales of securities will have on the market price of any securities of the Company that are issued and outstanding from time to time. Sales or issuances of substantial amounts of securities of the Company, or the perception that such sales could occur, may adversely affect prevailing market prices for the securities of the Company that are issued and outstanding from time to time. With any additional sale or issuance of securities of the Company, holders will suffer dilution with respect to voting power and may experience dilution in the Company’s earnings per share. Moreover, this Prospectus Supplement and the Base Shelf Prospectus may create a perceived risk of dilution resulting in downward pressure on the price of the Company’s issued and outstanding Common Shares, which could contribute to progressive declines in the prices of such securities.

The Company has Broad Discretion in the Use of the Net Proceeds from the Offering and May Use Them in Ways Other than as Described Herein.

Management of the Company will have broad discretion with respect to the application of net proceeds received by the Company under the Offering, if any, and may spend such proceeds in ways that do not improve the Company’s results of operations or enhance the value of the Common Shares or its other securities issued and outstanding from time to time. Any failure by management to apply these funds effectively could result in financial losses that could have a material adverse effect on the Company’s business or cause the price of the securities of the Company issued and outstanding from time to time to decline. Because of the number and variability of factors that will determine the Company’s use of such proceeds, if any, the Company’s ultimate use might vary substantially from its planned use. You may not agree with how the Company allocates or spends the proceeds from the Offering, if any.

No Current Market for Warrants

The Company has not applied to list the Warrants on the TSX, there is currently no market through which the Warrants may be sold and purchasers of the Offered Units may not be able to resell the Warrants purchased under this Prospectus. This may affect the pricing of the Warrants in the secondary market, the transparency and availability of trading prices, the liquidity of the Warrants, and the extent of issuer regulation.

The Warrants do not confer any rights of common share ownership on their holders, such as voting rights or the right to receive dividends, but rather merely represent the right to acquire Common Shares at a fixed price for a limited period of time. Specifically, commencing on the date of issuance, holders of the Warrants may exercise their right to acquire Common Shares and pay an exercise price of $0.70 per Warrant Share, subject to certain adjustments, prior to the date which is 24 months following the Closing Date, after which date any unexercised Warrants will expire and have no further value. Moreover, following this Offering, the market value of the Warrants, if any, is uncertain and there can be no assurance that the market value of the Warrants will equal or exceed their imputed offering price. There can be no assurance that the market price of the Common Shares will ever equal or exceed the exercise price of the Warrants, and consequently, whether it will ever be profitable for holders of the Warrants to exercise the Warrants.

Investors May Lose Their Entire Investment

An investment in the Offered Units is speculative and may result in the loss of an investor’s entire investment. Only potential investors who are experienced in high risk investments and who can afford to lose their entire investment should consider an investment in the Company.

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CONSOLIDATED CAPITALIZATION

The following table summarizes the consolidated capitalization of the Company as at the date of the Company’s Interim Financial Statements:

Description	Authorized	Outstanding as at June 30, 2020
Common Shares	Unlimited	633,376,453
Warrants	N/A	34,583,157
Stock Options	Limited(1)	50,352,500

_____ Note:

(1) Pursuant to the Company’s share-based compensation plan (the “ Plan ”) approved by shareholders of the Company on June 25, 2019, the Company may grant that number of incentive stock options that, together with any other awards outstanding under the Plan, is equal to 10% of the Common Shares then outstanding.

There have been no material changes to the share and loan capital of the Company on a consolidated basis since June 30, 2020 other than: (i) 30,000,000 Common Share purchase warrants were issued with an exercise price of C$0.40 and an expiry date of July 2, 2025; (ii) 353,000 Common Shares were issued pursuant to the exercise of stock options at an exercise price of C$0.25 per stock option; (iii) 353,000 Common Shares were issued pursuant to the exercise of stock options at an exercise price of C$0.40 per stock option; (iv) 85,000 Common Shares were issued pursuant to the exercise of Common Share purchase warrants at an exercise price of C$0.33 per warrant; and (v) an aggregate of 122,000 Common Shares were issued pursuant to the exercise of a combination of stock options and Common Share purchase warrants at an exercise price of C$0.28 per stock option or warrant, as applicable; and (vi) 100,000 stock options of the Company expired.

USE OF PROCEEDS

The net proceeds to the Company from the Offering will be approximately C$23,500,000, assuming the Over-Allotment Option is not exercised, and C$27,025,000 if the Over-Allotment Option is exercised in full, each figure presented after deducting the Underwriters’ Commission, which will be paid out of the proceeds of the Offering, and before deducting the expenses of the Offering (estimated to be C$375,000).

The net proceeds of the Offering (assuming no exercise of the Over-Allotment Option) are anticipated to be applied as follows, which assumes that no sales are being made to persons on the President’s List:

Use of Proceeds
Continued development of the Springpole Gold Project	C$10,000,000
Exploration and development of the Company's gold portfolio assets, including potential
acquisitions	C$10,000,000
Working capital and general corporate purposes	C$3,500,000
Total	C$23,500,000

The Company intends to spend the available funds as set forth above based on a budget which has been approved by the board of directors of the Company (the “ Board ”) consistent with established internal control guidelines. The anticipated use of net proceeds from the Offering, as detailed above, is based on the best estimates prepared by management of the Company.

Pursuant to the Offering, if the Over-Allotment Option is exercised in full, the Company will receive additional net proceeds of $3,525,000 after deducting the Underwriters’ Fee in respect of such exercise and assuming no sales to persons on the President’s List. The net proceeds from the exercise of the Over-Allotment Option, if any, will be applied towards the uses set forth above. There is no assurance that the Over-Allotment Option will be exercised, in part or in full.

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Although the Company intends to use the net proceeds from the Offering as set forth above, the actual allocation of the net proceeds may vary from those allocations set out above, depending on future developments in the Company’s business operations or unforeseen events, including those listed under the “ Risk Factors ” section of this Prospectus Supplement and the Base Shelf Prospectus. For example, the Company had negative operating cash flow for the fiscal year ended December 31, 2019 and the six-month period ended June 30, 2020. The Company’s cash and cash equivalents total approximately $8.5 million as at August 19, 2020. To the extent the Company has negative cash flows in future periods, the Company may use a portion of its general working capital to fund such negative cash flow. Prospective purchasers are cautioned that, notwithstanding the Company’s current intentions regarding the use of the net proceeds of the Offering, there may be circumstances where a reallocation of the net proceeds may be advisable for reasons that management believes, in its discretion, are in the Company’s best interests.

DESCRIPTION OF SECURITIES BEING DISTRIBUTED

Authorized Capital

The authorized capital of the Company consists of an unlimited number of Common Shares. As at June 30, 2020, there were 633,376,453 Common Shares issued and outstanding. As at the date of this Prospectus Supplement, there were 634,608,953 Common Shares issued and outstanding.

Unit Shares and Warrant Shares

The Unit Shares and Warrant Shares will have all of the characteristics, rights and restrictions of the Common Shares. The holders of Common Shares are entitled to receive notice of and to attend all annual and special meetings of the Company’s shareholders and to one vote in respect of each Common Share held at the record date for each such meeting. The holders of Common Shares are entitled, at the discretion of the Board, to receive out of any or all of the Company’s profits or surplus properly available for the payment of dividends, any dividend declared by the Board and payable by the Company on the Common Shares. The holders of Common Shares will participate pro rata in any distribution of the assets of the Company upon liquidation, dissolution or winding-up or other distribution of the assets of the Company. Such participation will be subject to the rights, privileges, restrictions and conditions attached to any of the Company’s securities issued and outstanding at such time ranking in priority to the Common Shares upon the liquidation, dissolution or winding-up of the Company. Common Shares are issued only as fully paid and are non-assessable.

Warrants

The Warrants will be governed by the terms of a warrant indenture (the “ Warrant Indenture ”) to be dated as of the Closing Date between the Company and Computershare Trust Company of Canada (the “ Warrant Agent ”), as warrant agent. The following summary of certain anticipated provisions of the Warrant Indenture does not purport to be complete and is subject in its entirety to the detailed provisions of the Warrant Indenture. Reference is made to the Warrant Indenture for the full text of the attributes of the Warrants which will be filed by the Company under its profile on www.sedar.com following the closing of the Offering. A register of holders will be maintained at the principal offices of the Warrant Agent in Vancouver, British Columbia.

The Unit Shares and the Warrants comprising the Offered Units will separate following the closing of the Offering. Each Warrant will entitle the holder to acquire, subject to adjustment in certain circumstances, one Warrant Share at an exercise price of $0.70 on or before the date that is 24 months from the Closing Date, after which time the Warrants will be void and of no value.

The Warrant Indenture will provide for adjustment in the number of Warrant Shares issuable upon the exercise of the Warrants and/or the exercise price per Warrant Share upon the occurrence of certain events, including:

(i) the issuance of Common Shares or securities exchangeable for or convertible into Common Shares to all or substantially all of the holders of the Common Shares as a stock dividend or other distribution (other than a distribution of Common Shares upon the exercise of Warrants);
(ii) the subdivision, redivision or change of the Common Shares into a greater number of shares;
(iii) the reduction, combination or consolidation of the Common Shares into a lesser number of shares;
(iv) the issuance to all or substantially all of the holders of the Common Shares of rights, options or warrants under which such holders are entitled, during a period expiring not more than 45 days after the record date for such issuance, to subscribe for or purchase Common Shares, or securities exchangeable for or convertible into Common Shares, at a price

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per share to the holder (or at an exchange or conversion price per share) of less than 95% of the “current market price”, as defined in the Warrant Indenture, for the Common Shares on such record date; and

(v) the issuance or distribution to all or substantially all of the holders of the Common Shares of shares of any class other than the Common Shares, rights, options or warrants to acquire Common Shares or securities exchangeable or convertible into Common Shares, of evidences of indebtedness, or any property or other assets.

The Warrant Indenture will also provide for adjustments in the class and/or number of securities issuable upon exercise of the Warrants and/or exercise price per security in certain cases in the event of the following additional events: (a) reclassifications of the Common Shares or a capital reorganization of the Company (other than as described in clauses (i) or (ii) above), (b) consolidations, amalgamations, arrangements, mergers or other business combinations of the Company with or into another entity, or (c) any sale, lease, exchange or transfer of the undertaking or assets of the Company as an entirety or substantially as an entirety to another entity, in which case each holder of a Warrant which is thereafter exercised will receive, in lieu of Common Shares, the kind and number or amount of other securities or property which such holder would have been entitled to receive as a result of such event if such holder had exercised the Warrants prior to the event.

The Company will also covenant in the Warrant Indenture that, during the period in which the Warrants are exercisable, it will give notice to holders of Warrants of certain stated events, including events that would result in an adjustment to the exercise price for the Warrants or the number of Warrant Shares issuable upon exercise of the Warrants, at least 14 days prior to the record date or effective date, as the case may be, of such events.

No fractional Warrant Shares will be issuable upon the exercise of any Warrants, and no cash or other consideration will be paid in lieu of fractional shares. Holders of Warrants will not have any voting or pre-emptive rights or any other rights which a holder of Common Shares would have. The Warrants will be transferable in accordance with the terms of the Warrant Indenture.

From time to time, the Company and the Warrant Agent, without the consent of the holders of Warrants, may amend or supplement the Warrant Indenture for certain purposes, including curing defects or inconsistencies or making any change that does not adversely affect the rights of any holder of Warrants. Any amendment or supplement to the Warrant Indenture that adversely affects the interests of the holders of the Warrants may only be made by “extraordinary resolution”, which will be defined in the Warrant Indenture as a resolution either (a) passed at a meeting of the holders of Warrants at which there are holders of Warrants present in person or represented by proxy representing at least 10% of the aggregate number of the then outstanding Warrants and passed by the affirmative vote of holders of Warrants representing not less than 66⅔% of the aggregate number of all the then outstanding Warrants represented at the meeting and voted on the poll upon such resolution or (b) adopted by an instrument in writing signed by the holders of not less than 66⅔% of the aggregate number of all then outstanding Warrants.

Neither the Warrants nor the Warrant Shares have been registered under the U.S. Securities Act or any state securities laws, and the Warrants may be exercised by a U.S. Person only if the Warrant Shares are registered under the U.S. Securities Act and applicable state securities laws or an exemption from such registration requirements is available.

PLAN OF DISTRIBUTION

Pursuant to the Underwriting Agreement, the Company has agreed to sell and the Underwriters have severally agreed to purchase on the Closing Date, an aggregate of 50,000,000 Offered Units at a price of C$0.50 per Offered Unit, payable in cash to the Company against delivery of such Offered Units. The obligations of the Underwriters under the Underwriting Agreement may be terminated at their discretion on the basis of “regulatory out”, “disaster out”, “material change out” and “breach out” provisions in the Underwriting Agreement, including as a result of the COVID-19 pandemic, but only to the extent that there are material adverse developments related thereto after August 17, 2020 and may also be terminated upon the occurrence of certain other stated events. The Underwriters are, however, severally (not jointly and not jointly and severally) obligated to take up and pay for all of the Offered Units that they have agreed to purchase if any of the Offered Units are purchased under the Underwriting Agreement. The terms of the Offering and the Offering Price have been determined by negotiation among the Company and the Underwriters with reference to the market price of the Common Shares on the TSX and other factors.

The closing of the Offering is expected to take place on August 26, 2020, or such other date as the Company and the Underwriters may agree.

Subject to certain qualifications and limitations, the Company has agreed to indemnify the Underwriters and their respective affiliates and each of their directors, officers, employees and shareholders of the Underwriters and their affiliates against certain liabilities,

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including, without restriction, civil liabilities under Canadian securities legislation, and to contribute to any payments the Underwriters may be required to make in respect thereof.

Pursuant to the Underwriting Agreement, the Company has agreed to pay the Underwriters a fee of C$0.03 per Offered Unit (including, for certainty, the Over-Allotment Units pursuant to the exercise of the Over-Allotment Option), other than in respect of sales to persons on the President’s List purchasing Offered Units for gross proceeds of up to $1,000,000, on which a fee of C$0.005 will be paid per Offered Unit.

The Company has granted to the Underwriters the Over-Allotment Option, exercisable in whole or in part in the sole discretion of the Underwriter for a period of 30 days from and including the Closing Date, to purchase up to an additional 7,500,000 Over-Allotment Units on the same terms as set forth above solely to cover over-allocations, if any, and for market stabilization purposes. The Prospectus also qualifies the grant of the Over-Allotment Option and distribution of the Over-Allotment Units issuable upon the exercise of the Over-Allotment Option. A purchaser who acquires Over-Allotment Units forming part of the Underwriters’ over-allocation position acquires such Over-Allotment Units under the Prospectus, regardless of whether the over-allocation position is ultimately filled through the exercise of the Over-Allotment Option or secondary market purchases. If the Over-Allotment Option is exercised in full, the aggregate Underwriters’ Commission payable by the Company in respect of the Over-Allotment Units issued in connection therewith will be C$1,725,000, assuming no sales to persons on the President’s List.

The Underwriters propose to offer the Offered Units initially at the Offering Price. After the Underwriters have made a reasonable effort to sell all of the Offered Units at the Offering Price, the price at which the Offered Units are distributed pursuant to the Prospectus may be decreased and may be further changed from time to time to an amount not greater than the Offering Price, and the compensation realized by the Underwriters will be decreased by the amount that the aggregate price paid by purchasers for the Offered Units distributed pursuant to the Prospectus is less than the Offering Price.

In connection with the Offering, the Underwriters may over-allocate or effect transactions which stabilize or maintain the market price of the Common Shares at levels other than those which otherwise might prevail on the open market, including: stabilizing transactions; short sales (i.e., the sale by the Underwriters of a greater number of Common Shares than they are required to purchase in the Offering); and purchases to cover positions created by short sales; and syndicate covering transactions. Such transactions, if commenced, may be discontinued at any time. Stabilizing transactions consist of bids or purchases made for the purpose of preventing or retarding a decline in the market price of the Common Shares while the Offering is in progress. The Underwriters must close out any short position by purchasing Common Shares in the open market. A short position is more likely to be created if the Underwriters are concerned that there may be downward pressure on the price of the Common Shares in the open market that could adversely affect investors who purchase in the Offering.

In addition, in accordance with rules and policy statements of certain Canadian securities regulators, the Underwriters may not, at any time during the period of distribution, bid for or purchase Common Shares. The foregoing restriction is, however, subject to exceptions where the bid or purchase is not made for the purpose of creating actual or apparent active trading in, or raising the price of, the Common Shares. These exceptions include a bid or purchase permitted under the by-laws and rules of applicable regulatory authorities and the TSX, including the Universal Market Integrity Rules for Canadian Marketplaces, relating to market stabilization and passive market making activities and a bid or purchase made for and on behalf of a customer where the order was not solicited during the period of distribution.

As a result of these activities, the price of the Common Shares may be higher than the price that otherwise might exist in the open market. If these activities are commenced, they may be discontinued by the Underwriters at any time. The Underwriters may carry out these transactions on any stock exchange on which the Common Shares are listed, in the over-the-counter market, or otherwise.

Offering Jurisdictions

The Offered Units will be offered by the Canadian Underwriters in all of the provinces of Canada, other than Québec, and by the Underwriters to certain qualified investors in the United States through the Underwriters or through their United States registered broker-dealer affiliates, as applicable. Other than in Canada and the United States, no action has been taken by the Company or the Underwriters that would permit a public offering of the Offered Units pursuant to the Prospectus in any jurisdiction where action for that purpose is required. Subject to compliance with applicable law, the Underwriters may also offer the Offered Units outside of Canada and the United States. The Company is not making, and the Prospectus does not constitute, an offer to sell or a solicitation of an offer to buy the Offered Units in any jurisdiction where such offer or solicitation is not permitted. HCW will not, directly or indirectly, solicit offers to purchase or sell Offered Units in Canada.

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Settlement

Subscriptions for the Offered Units will be received subject to rejection or allotment in whole or in part and the right is reserved to close the subscription books at any time without notice.

It is anticipated that the Unit Shares and Warrants comprising the Offered Units will be delivered under the book-based system through CDS or its nominee and deposited in electronic form, or will otherwise be delivered to the Underwriters registered as directed by the Underwriters, on the Closing Date. Except in limited circumstances, a purchaser of Offered Units will receive only a customer confirmation from the registered dealer from or through which the Offered Units are purchased and who is a CDS depository service participant. CDS will record the CDS participants who hold Unit Shares and Warrants on behalf of owners who have purchased Offered Units in accordance with the book-based system. No definitive certificates will be issued unless specifically requested or required.

Trades in the secondary market generally are required to settle in two business days, unless the parties to any such trade expressly agree otherwise. Accordingly, purchasers who wish to trade the Offered Units or the Unit Shares or Warrants comprising the Offered Units, that they have purchased pursuant to the Offering prior to the eighth business day after the date of this Prospectus Supplement will be required, by virtue of the fact that the Offered Units will initially settle T+8, to specify an alternate settlement cycle at the time of any such trade to prevent a failed settlement. Purchasers of Offered Units who wish to trade such Offered Units prior to the eighth business day after the date of this Prospectus Supplement should consult their own advisor.

The Company has applied to the TSX for approval of the listing of the Unit Shares and Warrant Shares to be distributed pursuant to the Prospectus. Listing will be subject to the Company fulfilling all of the listing requirements of the TSX.

Standstill

Pursuant to the Underwriting Agreement, the Company has agreed that it shall not issue any Common Shares or securities convertible into Common Shares for a period of 90 days following the Closing Date, without the prior written consent of the Lead Underwriter, which consent will not be unreasonably withheld or delayed, except in conjunction with (i) the grant or vesting of restricted share units or the grant or exercise of share purchase options and other similar issuances pursuant to the Company’s share compensation arrangements; (ii) arm’s length acquisitions; (iii) the exercise of any outstanding warrants, options, rights or other convertible securities; and (iv) to satisfy existing contractual obligations.

Lock Up

Pursuant to the Underwriting Agreement, the Company has agreed to cause its senior management and directors to enter into lock-up agreements to be executed concurrently with the closing of the Offering, agreeing not to, for a period of 90 days following the closing of the Offering, directly or indirectly, offer, sell, dispose of or otherwise monetize the economic value of any securities in the Company beneficially owned by such shareholder, without the prior written consent of the Lead Underwriter, which consent will not be unreasonably withheld, subject to the following exceptions: (i) if the Company receives an offer, which has not been withdrawn, to enter into a transaction or arrangement, or proposed transaction or arrangement, pursuant to which, if entered into or completed substantially in accordance with its terms, a party could, directly or indirectly acquire an interest (including an economic interest) in, or become the holder of, 100% of the total number of Common Shares, whether by way of takeover offer, scheme of arrangement, shareholder approved acquisition, capital reduction, share buyback, securities issue, reverse takeover, dual-listed Company structure or other synthetic merger, transaction or arrangement; (ii) in respect of transfers to affiliates of such shareholder; (iii) as a result of the death of any individual shareholder; or (iv) pursuant to a pledge as security for indebtedness owing to a bona fide lender and/or any sale of the securities upon such lender realizing on such security.

The lock-up agreements shall not apply to the 100,000 options held by the Company’s Chief Financial Officer, expiring in Q3 2020 and the underlying shares to be issued upon exercise of such options. The lock-up restriction noted above will terminate for any officer or director of the Company that ceases to be such during the 90-day lock-up period.

U.S. Securities Laws Matters

The Offered Units, Unit Shares and Warrants have not been and will not be registered under the U.S. Securities Act or any state securities laws, and accordingly may not be offered or sold within the United States or to, or for the account or benefit of, U.S. Persons, except in transactions exempt from the registration requirements of the U.S. Securities Act and applicable state securities laws. Each Underwriter, on its own behalf and on behalf of each of its United States registered broker-dealer affiliates (“ U.S. Affiliates ”), has agreed that, except as permitted by the Underwriting Agreement (subject to all the agreements, covenants and restrictions set forth therein and exhibits and schedules thereto) and as expressly permitted by applicable United States federal and state securities laws, it will not offer or sell the

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Offered Units, Unit Shares or Warrants, as part of its distribution at any time, within the United States or to, or for the account or benefit of, U.S. Persons and that all offers and sales of the Offered Units, Unit Shares and Warrants will otherwise be made outside of the United States in accordance with Rule 903 of Regulation S under the U.S. Securities Act. Terms used in this and the next paragraph have the meanings given to them in Regulation S under the U.S. Securities Act. The Underwriting Agreement (and the exhibits and schedules thereto) permit the Underwriters to offer and resell the Offered Units, Unit Shares and Warrants that they have acquired pursuant to the Underwriting Agreement to certain “qualified institutional buyers”, as such term is defined in Rule 144A under the U.S. Securities Act (“ Rule 144A ”), in the United States, provided such offers and sales are made in accordance with Rule 144A and applicable state securities laws.

In addition, until 40 days after the commencement of the Offering, an offer or sale of Offered Units, Unit Shares or Warrants within the United States by any dealer (whether or not participating in the Offering) may violate the registration requirements of the U.S. Securities Act if such offer or sale is made otherwise than in accordance with Rule 144A.

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PRIOR SALES

Common Shares

The following table summarizes details of the Common Shares issued by the Company during the 12-month period prior to the date of this Prospectus Supplement:

ectus Supplement:
	Weighted Average Price Per
Date of Issuance	Common Share ($)	Aggregate Number of Common Shares Issued
December 18, 2019(3)	$0.27	7,775,250
January 15, 2020(4)	$0.27	2,777,777
January 30, 2020(1)	$0.15	400,000
February 14, 2020(3)	$0.25	10,000,000
February 28, 2020(3)	$0.22	23,328,818
March 6, 2020(3)	$0.22	4,091,500
April 14, 2020(5)	$0.2407	72,000
April 15, 2020(5)	$0.24	15,500
April 16, 2020(5)	$0.24	42,000
April 22, 2020(5)	$0.24	57,000
April 23, 2020(5)	$0.2436	315,500
April 24, 2020(5)	$0.24	30,000
June 12, 2020(1)	$0.25	50,000
June 25, 2020(1)	$0.25	50,000
June 29, 2020(1)	$0.25	125,000
July 3, 2020(1)	$0.25	62,500
July 8, 2020(1)	$0.40	125,000
July 9, 2020(1)	$0.40	75,000
July 10, 2020(2)	$0.33	60,000
July 14, 2020(1)	$0.40	50,000
July 17, 2020(2)	$0.33	25,000
July 21, 2020(1)	$0.40	50,000
July 23, 2020(1)	$0.40	100,000
July 27, 2020(1)	$0.40	200,000
July 28, 2020(1)	$0.25	53,000
July 30, 2020(1), (2)	$0.28	122,000
August 5, 2020(1)	$0.25	187,500
August 7, 2020(1)	$0.40	30,000
August 13, 2020(1)	$0.25	50,000
TOTAL		50,320,345

Notes:

(1) Issued pursuant to the exercise of stock options.

(2) Issued pursuant to the exercise of Common Share purchase warrants.

(3) Issued pursuant to private placement offerings completed by the Company on such date.

(4) Issued pursuant to an agreement with Ausenco Engineering Canada Ltd. in connection with completing the Springpole Pre-Feasibility Study.

(5) Issued pursuant to sales under the Company’s at-the-market facility.

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Warrants

The following table summarizes details of the Common Share purchase warrants issued by the Company during the 12-month period prior to the date of this Prospectus Supplement:

Date of Issuance	Number of Warrants Issued	Exercise Price	Expiry Date
February 14, 2020	5,000,000	$0.33	February 14, 2023
February 28, 2020	11,664,409	$0.33	February 28, 2023
March 6, 2020	2,045,750	$0.33	March 6, 2023
July 2, 2020	30,000,000	$0.40	July 2, 2025

As of the date hereof, there are 64,405,657 warrants of the Company outstanding.

Stock Options

The following table summarizes details of the stock options issued by the Company during the 12-month period prior to the date of this Prospectus Supplement:

Supplement:
Date of Grant	Number of Stock Options Granted	Exercise Price	Expiry Date
January 31, 2020	8,750,000	$0.25	January 31, 2025
April 1, 2020	1,100,000	$0.25	April 1, 2025

As of the date hereof, there are 49,047,500 stock options of the Company outstanding.

TRADING PRICE AND VOLUME

The Common Shares trade on the TSX under the symbol “FF”. On August 19, 2020, the last trading day completed prior to the filing of this Prospectus Supplement, the closing price of the Common Shares on the TSX was $0.46. The price ranges and trading volumes of the Common Shares for each month from August 2019 to August 2020, as reported by the TSX, are set out below:

Month August 1 – 19, 2020 July 2020 June 2020 May 2020 April 2020 March 2020 February 2020 January 2020 December 2019 November 2019 October 2019	High $0.600 $0.540 $0.430 $0.295 $0.255 $0.230 $0.280 $0.275 $0.265 $0.245 $0.250	Low $0.445 $0.420 $0.295 $0.210 $0.175 $0.115 $0.190 $0.225 $0.215 $0.205 $0.215	Total Volume
			21,399,548 32,848,762 30,549,344 18,103,239 11,285,777 22,346,140 14,075,624 9,495,626 15,763,133 7,306,795 8,791,838

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Month September 2019 August 2019	High $0.295 $0.335	Low $0.240 $0.250	Total Volume
			10,339,786 15,824,976

CERTAIN CANADIAN FEDERAL INCOME TAX CONSIDERATIONS

In the opinion of Bennett Jones LLP, counsel to the Company, and Wildeboer Dellelce LLP, counsel to the Underwriters, the following is a summary of certain of the principal Canadian federal income tax considerations under the Tax Act generally applicable to a holder (a “ Holder ”) who acquires Unit Shares and Warrants comprising the Offered Units and the Warrant Shares issuable upon exercise of the Warrants (the “ Securities ”) pursuant to the Offering and who, for the purposes of the Tax Act and at all relevant times, deals at arm's length with the Company and the Underwriters, is not affiliated with the Company or the Underwriters, and who acquires and holds the Securities as capital property. Generally, the Securities will be considered to be capital property to a Holder thereof provided that the Holder does not use the Securities in the course of carrying on a business of trading or dealing in securities and such Holder has not acquired the Securities in one or more transactions considered to be an adventure or concern in the nature of trade.

This summary is based upon the current provisions of the Tax Act in force as of the date hereof and counsels’ understanding of the current administrative policies and assessing practices of the Canada Revenue Agency (the “ CRA ”) which have been published in writing and made publicly available prior to the date hereof. This summary takes into account all specific proposals to amend the Tax Act publicly announced by or on behalf of the Minister of Finance (Canada) prior to the date hereof (the “ Tax Proposals ”) and assumes that the Tax Proposals will be enacted in the form proposed, although no assurance can be given that the Tax Proposals will be enacted in their current form or at all. This summary does not otherwise take into account or anticipate any changes in law or in the administrative policies or assessing practices of the CRA, whether by administrative, legislative, governmental or judicial decision or action, nor does it take into account or consider other federal or any provincial, territorial or foreign income tax legislation or considerations, which may differ significantly from the Canadian federal income tax considerations discussed in this summary. The provisions of provincial income tax legislation vary from province to province in Canada and in some cases differ from the Tax Act.

This summary is of a general nature only, is not exhaustive of all possible Canadian federal income tax considerations and is not intended to be, nor should it be construed to be, legal or tax advice to any particular Holder and no representations with respect to the income tax considerations applicable to any particular Holder are made. The relevant tax considerations applicable to acquiring holding and disposing of Securities may vary according to the status of the purchaser, the jurisdiction in which the purchaser resides or carries on business and the purchaser’s own particular circumstances. Holders should consult their own tax advisors with respect to their particular circumstances.

Allocation of Cost

A Holder who acquires Offered Units pursuant to this Offering will be required to allocate the purchase price paid for each Offered Unit on a reasonable basis between the Unit Share and the one-half Warrant comprising each Offered Unit in order to determine their respective costs to such Holder for the purposes of the Tax Act. Holders should consult their own tax advisors in this regard.

For its purposes, the Company intends to allocate $0.48 of the issue price of each Offered Unit as consideration for the issue of each Unit Share and $0.02 of the issue price of each Offered Unit for the issue of each one-half of one Warrant ($0.04 for each Warrant). Although the Company believes that this allocation is reasonable, it is not binding on the CRA or the Holder. Counsel to each of the Company and to the Underwriters express no opinion with respect to the foregoing allocation.

Adjusted Cost Base of Unit Shares

The adjusted cost base to a Holder of each Unit Share comprising a part of a Offered Unit acquired pursuant to this Offering will be determined by averaging the cost of such Unit Share with the adjusted cost base to such Holder of all other Common Shares (if any) held by the Holder as capital property immediately prior to the acquisition.

Exercise of Warrants

The exercise of a Warrant will not constitute a disposition of property for purposes of the Tax Act and consequently no gain or loss will be realized by a Holder upon the exercise of a Warrant. When a Warrant is exercised, the Holder’s cost of the Warrant Share acquired

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thereby will be equal to the adjusted cost base of the Warrant to such Holder, plus the amount paid on the exercise of the Warrant to acquire the Warrant Share. For the purpose of computing the adjusted cost base to a Holder of each Warrant Share acquired on the exercise of a Warrant the cost of such Warrant Share must be averaged with the adjusted cost base to such Holder of all other Common Shares (if any) held by the Holder as capital property immediately prior to the exercise of the Warrant.

Resident Holders

The following portion of this summary applies to Holders who are, or are deemed to be, resident in Canada for the purposes of the Tax Act at all relevant times (“ Resident Holders ”).

This portion of the summary does not apply to a Resident Holder: (i) that is a “financial institution” for the purposes of the mark-tomarket rules contained in the Tax Act (as that term is defined in the Tax Act); (ii) that is a “specified financial institution” (as defined in the Tax Act); (iii) an interest in which would be a “tax shelter investment” (as defined in the Tax Act); (iv) that enters into, or has entered into, a “derivative forward agreement” or “synthetic disposition arrangement” (each as defined in the Tax Act) in respect of the Securities; (v) that has made a functional currency reporting election under the Tax Act; or (vi) that receives dividends on the Unit Shares or the Warrant Shares, as the case may be, under or as part of a “dividend rental arrangement” (as defined in the Tax Act); (vii) that is a partnership; or (viii) that is exempt from tax under Part I of the Tax Act. Such Resident Holders should consult their own tax advisors with respect to an investment hereunder.

Certain Resident Holders to whom Unit Shares or Warrant Shares, as the case may be, might not otherwise constitute capital property may make, in certain circumstances, an irrevocable election under subsection 39(4) of the Tax Act to deem the Unit Shares and Warrant Shares, as the case may be, and every other “Canadian security” (as defined in the Tax Act) held by such persons, in the taxation year the election is made and in all subsequent taxation years to be capital property. Such election is not available in respect of the Warrants. Resident Holders should consult their own tax advisors regarding the availability or desirability of this election in their particular circumstances.

Expiry of Warrants

In the event of the expiry of an unexercised Warrant, a Resident Holder will generally realize a capital loss equal to the Resident Holder's adjusted cost base of such Warrant immediately before its expiry. The tax treatment of capital gains and capital losses is discussed in greater detail below under " Capital Gains and Capital Losses ".

Dividends

Dividends received or deemed to be received on the Unit Shares and Warrant Shares, as the case may be, will be included in computing a Resident Holder’s income. In the case of an individual (other than certain trusts), such dividends will be subject to the gross-up and dividend tax credit rules normally applicable in respect of taxable dividends received from “taxable Canadian corporations” (as defined in the Tax Act). An enhanced dividend tax credit will be available to individuals (other than certain trusts) in respect of “eligible dividends” (as defined in the Tax Act) designated by the Company in accordance with the provisions of the Tax Act. There may be limitations on the Company’s ability to designate dividends as “eligible dividends”.

Dividends received or deemed to be received by a corporation that is a Resident Holder on the Unit Shares or Warrant Shares, as the case may be, must be included in computing its income but generally will be deductible in computing the corporation's taxable income. In certain circumstances, subsection 55(2) of the Tax Act would treat a taxable dividend received (or deemed to be received) by a Resident Holder that is a corporation as proceeds of a disposition or a capital gain.

A Resident Holder that is a “private corporation” or a "subject corporation" (each as defined in the Tax Act) will generally be liable to pay a tax under Part IV of the Tax Act (refundable under certain circumstances) on dividends received or deemed to be received on the Unit Shares or Warrant Shares, as the case may be, to the extent such dividends are deductible in computing the Resident Holder’s taxable income. Resident Holders that are corporations should consult their own tax advisers regarding their particular circumstances.

Dispositions of Unit Shares, Warrant Shares and Warrants

Upon a disposition (or a deemed disposition) of a Unit Share or a Warrant Share (other than to the Company in a transaction that is not a sale in the open market) or a Warrant (other than on the exercise of the Warrant), a Resident Holder generally will realize a capital gain (or a capital loss) equal to the amount by which the proceeds of disposition of such Security, net of any reasonable costs of

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disposition, exceed (or are exceeded by) the adjusted cost base of such Security, to the Resident Holder. The tax treatment of capital gains and capital losses is discussed in greater detail below under “Capital Gains and Capital Losses” .

Capital Gains and Capital Losses

Generally, a Resident Holder is required to include in computing its income for a taxation year one-half of the amount of any capital gain (a “ taxable capital gain ”) realized in the year. Subject to and in accordance with the provisions of the Tax Act, a Resident Holder is required to deduct one-half of the amount of any capital loss (an “ allowable capital loss ”) realized in a taxation year from taxable capital gains realized in the year by such Resident Holder. Allowable capital losses in excess of taxable capital gains realized in a taxation year may be carried back and deducted against taxable capital gains in any of the three preceding taxation years or in any subsequent taxation year to the extent and under the circumstances described in the Tax Act.

The amount of any capital loss realized on the disposition or deemed disposition of Unit Shares or Warrant Shares, as the case may be, by a Resident Holder that is a corporation may be reduced by the amount of dividends received or deemed to have been received by it on such Unit Shares or Warrant Shares, or shares substituted for such Unit Shares or Warrant Shares, as the case may be, to the extent and in the circumstance specified by the Tax Act. Similar rules may apply where a Unit Share or Warrant Share, as the case may be, is owned by a partnership or trust of which a corporation, trust or partnership is a member or beneficiary. Resident Holders to whom these rules may be relevant should consult their own tax advisors.

Refundable Tax

A Resident Holder that is throughout the relevant taxation year a “Canadian-controlled private corporation” (as defined in the Tax Act) will be liable to pay an additional tax under Part I of the Tax Act (refundable under certain circumstances) on its “aggregate investment income” (as defined in the Tax Act) for the year which includes taxable capital gains realized on the disposition of their Unit Shares, Warrant Shares and Warrants and certain dividends.

Minimum Tax

Capital gains realized and dividends received or deemed to be received by a Resident Holder that is an individual (other than certain trusts) may give rise to minimum tax under the Tax Act.

Non-Resident Holders

The following portion of this summary is generally applicable to Holders who (i) for the purposes of the Tax Act or any other applicable tax treaty or convention, are not and will not be deemed to be resident in Canada at any time while they hold the Securities; and (ii) do not use or hold (or be deemed to use or hold) the Securities in the course of carrying on a business in Canada (“ Non-Resident Holders ”). Special rules, which are not discussed in this summary, may apply to a Non-Resident Holder that is an insurer carrying on business in Canada and elsewhere or that is an “authorized foreign bank” (as defined in the Tax Act). Such Non-Resident Holders should consult their own tax advisors.

Dividends

Dividends paid or credited or deemed to be paid or credited to a Non-Resident Holder by the Company on the Unit Shares or Warrant Shares, as the case may be, are subject to Canadian withholding tax at the rate of 25% on the gross amount of the dividend unless such rate is reduced by the terms of an applicable tax treaty or convention. For example, under the Canada-United States Income Tax Convention (1980), as amended (the “ Treaty ”), the rate of withholding tax on dividends paid or credited to a Non-Resident Holder who is resident in the U.S. for purposes of the Treaty, entitled to full benefits under the Treaty and is the beneficial owner of the dividend (a “ U.S. Holder ”), is generally limited to 15% of the gross amount of the dividend (or 5% in the case of a U.S. Holder that is a company beneficially owning at least 10% of the Company’s voting shares). Non-Resident Holders should consult their own tax advisors .

Dispositions of Unit Shares, Warrant Shares and Warrants

A Non-Resident Holder generally will not be subject to tax under the Tax Act in respect of a capital gain realized on the disposition or deemed disposition of a Security (as applicable), unless the Security constitutes “taxable Canadian property” (as defined in the Tax Act)

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of the Non-Resident Holder for purposes of the Tax Act, and the gain is not exempt from Canadian tax pursuant to the terms of an applicable income tax treaty or convention.

Provided the Common Shares are listed on a “designated stock exchange”, as defined in the Tax Act (which currently includes the TSX), at the time of disposition, the Securities generally will not constitute “taxable Canadian property” of a Non-Resident Holder at that time, unless at any time during the 60-month period immediately preceding the disposition the following two conditions are met concurrently: (i) (a) the Non-Resident Holder, (b) persons with whom the Non-Resident Holder does not deal at arm’s length for purposes of the Tax Act, (c) partnerships in which the Non-Resident Holder or persons described in (b) hold a membership interest (either directly or indirectly through one or more partnerships), or (d) the Non-Resident Holder together with such persons and partnerships described in (b) and (c), owned 25% or more of the issued shares of any class or series of shares of the Company; and (ii) more than 50% of the fair market value of the Common Shares was derived directly or indirectly from one or any combination of (a) real or immovable property situated in Canada, (b) “Canadian resource properties” (as defined in the Tax Act), (c) “timber resource properties” (as defined in the Tax Act) or (d) an option in respect of, or an interest or right in any such properties described in (a) to (c), whether or not such property exists.

Notwithstanding the foregoing, a Unit Share, a Warrant Share or a Warrant may in certain circumstances be deemed to be “taxable Canadian property” of a Non-Resident Holder for purposes of the Tax Act. A Non-Resident Holder’s capital gain (or capital loss) in respect of Securities that constitute or are deemed to constitute “taxable Canadian property” (and are not exempt from tax under the Tax Act pursuant to an applicable income tax treaty or convention) will generally be computed in the manner described above under the heading “Resident Holders – Dispositions of Unit Shares and Warrants” .

Non-Resident Holders whose Securities may constitute taxable Canadian property should consult their own tax advisors.

LEGAL MATTERS

Certain legal matters in connection with the Offering will be passed upon on behalf of the Company by Bennett Jones LLP, Canadian counsel to the Company, and by Dorsey & Whitney LLP, United States counsel to the Company, and on behalf of the Underwriters by Wildeboer Dellelce LLP, Canadian counsel to the Underwriters, and by Nauth LPC, United States counsel to the Underwriters.

As of the date of this Prospectus Supplement, the partners and associates of each of the aforementioned firms beneficially own, directly or indirectly, in the aggregate less than 1% of the issued and outstanding securities of the Company.

AUDITOR, TRANSFER AGENT AND REGISTRAR

PricewaterhouseCoopers LLP is the auditor of the Company. PricewaterhouseCoopers LLP is independent within the meaning of PCAOB Rule 3520, Auditor Independence and the Chartered Professional Accountants of British Columbia Code of Professional Conduct.

The transfer agent and registrar for the Common Shares is Computershare Trust Company of Canada at its principal transfer offices in Vancouver, British Columbia.

STATUTORY AND CONTRACTUAL RIGHTS OF WITHDRAWAL AND RESCISSION

Securities legislation in certain of the provinces of Canada provides purchasers with the right to withdraw from an agreement to purchase securities. This right may be exercised within two business days after receipt or deemed receipt of a prospectus and any amendment. In several of the provinces, the securities legislation further provides a purchaser with remedies for rescission or, in some jurisdictions, revisions of the price or damages if the prospectus and any amendment contains a misrepresentation or is not delivered to the purchaser, provided that the remedies for rescission, revision of the price or damages are exercised by the purchaser within the time limit prescribed by the securities legislation of the purchaser’s province. The purchaser should refer to any applicable provisions of the securities legislation of the purchaser’s province for the particulars of these rights or consult with a legal advisor.

In an offering of warrants, investors are cautioned that the statutory right of action for damages for a misrepresentation contained in this Prospectus is limited, in certain provincial securities legislation, to the price at which the warrant is offered to the public under the prospectus offering. This means that, under the securities legislation of certain provinces, if the purchaser pays additional amounts upon conversion, exchange or exercise of the security, those amounts may not be recoverable under the statutory right of action for damages that applies in those provinces. The purchaser should refer to any applicable provisions of the securities legislation of the purchaser’s province for the particulars of this right of action for damages or consult with a legal adviser

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INTERESTS OF EXPERTS

All technical and scientific information discussed in this Prospectus Supplement or any documents incorporated by reference herein, including mineral resource estimates for the Company’s material properties, and all technical and scientific information for the Company’s other non-material projects, has been reviewed and approved by Hazel Mullin, P.Geo., the Company’s Director of Data Management and Technical Services who is a qualified person for the purposes of NI 43-101.

The following individuals prepared the technical report entitled “Preliminary Economic Assessment Update for the Springpole Gold Project, Ontario, Canada” dated November 5, 2019 with an effective date of September 1, 2019:

Dr. Gilles Arseneau, Ph.D., P.Geo., Associate Consultant, of SRK Consulting (Canada) Inc.;
Grant Carlson, P.Eng., Senior Consultant (Mining), of SRK Consulting (Canada) Inc.;
Bruce Andrew Murphy, P.Eng., Practice Leader (Geotechnical), of SRK Consulting (Canada) Inc.;
Neil Winkelmann, FAusIMM, Principal Consultant (Mining), of SRK Consulting (Canada) Inc.;
Michael Noël, P.Eng., Principal Consultant (GeoEnvironmental), of SRK Consulting (Canada) Inc.
Mark Liskowich, P.Geo, Principal Consultant (GeoEnvironmental), of SRK Consulting (Canada) Inc.
Michael Royle, M.App.Sci., P.Geo., Principal Hydrogeologist, of SRK Consulting (Canada) Inc.;
Mauricio Herrera, Ph.D., P.Eng., Principal Consultant (Surface Water Resources), of SRK Consulting (Canada) Inc.; and
Laurie Tahija, MMSA-QP, Principal Consultant (Processing), of M3 Engineering & Technology Corp.

Each of the abovementioned firms or persons hold, as either a registered or beneficial holder, less than one percent of the outstanding securities of First Mining or of any associate or affiliate of First Mining. None of the aforementioned firms or persons received any direct or indirect interest in any securities of First Mining or of any associate or affiliate of First Mining in connection with the preparation and review of any technical report. None of the aforementioned firms or persons, nor any directors, officers or employees of such firms or persons, are currently expected to be elected, appointed or employed as a director, officer or employee of the Company or of any associate or affiliate of the Company, other than Hazel Mullin, P.Geo., the Company’s Director of Data Management and Technical Services.

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CERTIFICATE OF THE COMPANY

Dated: August 19, 2020

This short form prospectus, together with the documents incorporated by reference, as supplemented by the foregoing, constitutes full, true and plain disclosure of all material facts relating to the securities offered by the short form prospectus and this supplement as required by the securities legislation of each of the provinces of Canada, except Québec.

FIRST MINING GOLD CORP.

(Signed) “Daniel W. Wilton” By: Daniel W. Wilton Chief Executive Officer	(Signed) “Andrew Marshall”
	By: Andrew Marshall Chief Financial Officer

ON BEHALF OF THE BOARD OF DIRECTORS

(Signed) “Keith Neumeyer” (Signed) “Raymond Polman” By: Keith Neumeyer By: Raymond Polman Director Director

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CERTIFICATE OF THE UNDERWRITERS

Dated: August 19, 2020

To the best of our knowledge, information and belief, the short form prospectus, together with the documents incorporated by reference, as supplemented by the foregoing, constitutes full, true and plain disclosure of all material facts relating to the securities offered by the short form prospectus and this supplement as required by the securities legislation of each of the provinces of Canada, except Québec.

CORMARK SECURITIES INC.

(Signed) “Darren Wallace”

By: Darren Wallace Managing Director, Investment Banking

BMO NESBITT BURNS INC .

(Signed) “Carter Hohmann”

By: Carter Hohmann Managing Director, Investment Banking

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This prospectus is a short form base shelf prospectus. This short form base shelf prospectus has been filed under legislation in each of the provinces of Canada that permits certain information about these securities to be determined after this prospectus has become final and that permits the omission from this prospectus of that information. The legislation requires the delivery to purchasers of a prospectus supplement containing the omitted information within a specified period of time after agreeing to purchase any of these securities, except in cases where an exemption from such delivery has been obtained.

No securities regulatory authority has expressed an opinion about these securities and it is an offence to claim otherwise. This short form base shelf prospectus constitutes a public offering of these securities only in those jurisdictions where they may be lawfully offered for sale therein and only by persons permitted to sell such securities. See “Plan of Distribution”.

Information has been incorporated by reference in this short form base shelf prospectus from documents filed with securities commissions or similar authorities in Canada. Copies of the documents incorporated herein by reference may be obtained on request without charge from the General Counsel & Corporate Secretary of First Mining Gold Corp. at Suite 1800 – 925 West Georgia Street, Vancouver, British Columbia V6C 3L2, and are also available electronically at www.sedar.com.

SHORT FORM BASE SHELF PROSPECTUS

New Issue June 24, 2019

==> picture [360 x 114] intentionally omitted <==

FIRST MINING GOLD CORP.

$100,000,000

Common Shares Preferred Shares Warrants Subscription Receipts Units

This short form base shelf prospectus (the “ Prospectus ”) relates to the offering for sale by First Mining Gold Corp. (the “ Company ”) from time to time, during the 25-month period that this Prospectus, including any amendments hereto, remains valid, of up to $100,000,000 (or the equivalent in other currencies based on the applicable exchange rate at the time of the offering) in the aggregate of: (i) common shares (“ Common Shares ”) in the capital of the Company; (ii) preferred shares (“ Preferred Shares ”) in the capital of the Company, issuable in series; (iii) warrants (“ Warrants ”) to purchase other Securities (as defined below) of the Company; (iv) subscription receipts (“ Subscription Receipts ”) convertible into other securities of the Company; and (v) units (“ Units ”) comprised of one or more of any of the other Securities, or any combination of such Securities (the Common Shares, Preferred Shares, Warrants, Subscription Receipts, and Units are collectively referred to herein as the “ Securities ”). The Securities may be offered in amounts, at prices and on terms to be determined based on market conditions at the time of sale and set forth in an accompanying prospectus supplement (each, a “ Prospectus Supplement ”). In addition, the Securities may be offered and issued in consideration for the acquisition of other businesses, assets or securities by the Company or one of its subsidiaries. The consideration for any such acquisition may consist of the Securities separately, a combination of Securities or any combination of, among other things, Securities, cash and assumption of liabilities.

The Company is permitted, under a multi-jurisdictional disclosure system adopted by the securities regulatory authorities in Canada and the United States, to prepare this Prospectus in accordance with the disclosure requirements of Canada. Prospective investors in the United States should be aware that such requirements are different from those of the United States. The financial statements incorporated by reference herein have been prepared in accordance with International Financial Reporting Standards (“IFRS”) as issued by the International Accounting Standards Board and thus may not be comparable to financial statements of United States companies.

The enforcement by investors of civil liabilities under the United States federal securities laws may be affected adversely by the fact that the Company is governed by the laws of British Columbia, Canada, that some or all of its officers and directors are residents of a foreign country, that some or all of the experts named in this Prospectus are, and the underwriters, dealers or agents named in any Prospectus Supplement may be, residents of a foreign country, and a substantial portion of the assets of the Company and said persons may be located outside of the United States.

THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE UNITED STATES SECURITIES AND EXCHANGE COMMISSION (THE “SEC”) NOR ANY STATE OR CANADIAN SECURITIES COMMISSION OR REGULATORY AUTHORITY NOR HAS THE SEC OR ANY STATE OR CANADIAN SECURITIES COMMISSION PASSED UPON THE ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENCE.

Prospective investors should be aware that the acquisition of the Securities may have tax consequences in Canada and the United States. Such consequences may not be described fully herein or in any applicable Prospectus Supplement. Prospective investors should read the tax discussion contained in this Prospectus under the heading “ Certain Federal Income Tax Considerations ” as well as the tax discussion, if any, contained in the applicable Prospectus Supplement with respect to a particular offering of Securities.

The specific terms of any Securities offered will be described in the applicable Prospectus Supplement including, where applicable: (i) in the case of Common Shares, the number of Common Shares offered, the offering price, whether the Common Shares are being offered for cash, and any other terms specific to the Common Shares; (ii) in the case of Preferred Shares, the designation of the particular series, the number of Preferred Shares offered, the offering price, any voting rights, any rights to receive dividends, any terms of redemption, any conversion or exchange rights and any other specific terms; (iii) in the case of Warrants, the number of Warrants being offered, the offering price, whether the Warrants are being offered for cash, the designation, number and terms of the other Securities purchasable upon exercise of the Warrants, and any procedures that will result in the adjustment of those numbers, the exercise price, the dates and periods of exercise and any other terms specific to the Warrants being offered; (iv) in the case of Subscription Receipts, the number of Subscription Receipts being offered, the offering price, whether the Subscription Receipts are being offered for cash, the terms, conditions and procedures for the conversion of the Subscription Receipts into other Securities, the designation, number and terms of such other Securities, and any other terms specific to the Subscription Receipts; and (v) in the case of Units, the number of Units being offered, the offering price and the number and terms of the Securities comprising the Units. A Prospectus Supplement relating to a particular offering of Securities may include terms pertaining to the Securities being offered thereunder that are not within the terms and parameters described in this Prospectus. Where required by statute, regulation or policy, and where the Securities are offered in currencies other than Canadian dollars, appropriate disclosure of foreign exchange rates applicable to the Securities will be included in the Prospectus Supplement describing the Securities.

All shelf information permitted under applicable laws to be omitted from this Prospectus will be contained in one or more Prospectus Supplements that will be delivered to purchasers together with this Prospectus except in cases where an exemption from such delivery has been obtained. Each Prospectus Supplement will be incorporated by reference into this Prospectus for the purposes of securities legislation as of the date of the Prospectus Supplement and only for the purposes of the distribution of the Securities to which the Prospectus Supplement pertains. Prospective investors should read this Prospectus and any applicable Prospectus Supplement carefully before investing in any Securities issued pursuant to this Prospectus.

The Company may offer and sell the Securities to or through underwriters or dealers purchasing as principals, and may also sell directly to one or more purchasers or through agents or pursuant to applicable statutory exemptions. See “ Plan of Distribution ”. The Prospectus Supplement relating to a particular offering of Securities will identify each underwriter, dealer or agent, as the case may be, engaged by the Company in connection with the offering and sale of the Securities, and will set forth the terms of the offering of such Securities, including, to the extent applicable, any fees, discounts or any other compensation payable to underwriters, dealers or agents in connection with the offering, the method of distribution of the Securities, the initial issue price (in the event that the offering is a fixed price distribution), the proceeds that the Company will or expects to receive, and any other material terms of the plan of distribution.

The Securities may be sold from time to time in one or more transactions at a fixed price or prices or at non-fixed prices. If offered on a non-fixed price basis, the Securities may be offered at market prices prevailing at the time of sale, at prices determined by reference to the prevailing price of a specified Security in a specified market or at prices to be negotiated with purchasers, in which case the compensation payable to an underwriter, dealer or agent in connection with any such sale will be decreased by the amount, if any, by which the aggregate price paid for Securities by the purchasers is less than the gross proceeds paid by the underwriter, dealer or agent to the Company. The price at which the Securities will be offered and sold may vary from purchaser to purchaser and during the period of distribution.

In connection with any offering of Securities, except as otherwise set out in a Prospectus Supplement relating to a particular offering of Securities, the underwriters, dealers or agents may over-allot or effect transactions which stabilize or maintain the market price of the Securities offered at a level above that which might otherwise prevail in the open market. Such transactions may be commenced, interrupted or discontinued at any time. However, no underwriter, dealer or agent involved in an “at-the-market distribution”, as defined in National Instrument 44-102 Shelf Distributions (“NI 44-102”), no affiliate of such an underwriter, dealer or agent and no person or company acting jointly or in concert with such an underwriter, dealer or agent will over-allot Securities in connection with such distribution or effect any other transactions that are intended to stabilize or maintain the market price of the Securities. A purchaser who acquires Securities forming part of the underwriters’, dealers’ or agents’ over-allotment position acquires those Securities under this Prospectus and the Prospectus Supplement relating to the particular offering of Securities, regardless of whether the overallotment position is ultimately filled through the exercise of the over-allotment option or secondary market purchases. See “ Plan of Distribution ”.

The issued and outstanding Common Shares of the Company trade on the Toronto Stock Exchange (the “ Exchange ”) under the symbol “FF”, on the OTC-QX under the symbol “FFMGF” and on the Frankfurt Stock Exchange under the symbol “FMG”. On June 21, 2019, the last trading day prior to the date of this Prospectus, the closing price of the Common Shares on the Exchange was $0.205.

Unless otherwise specified in the applicable Prospectus Supplement, each series or issue of Securities (other than Common Shares) will not be listed on any securities exchange. Accordingly, there is currently no market through which the Securities (other than Common Shares) may be sold and purchasers may not be able to resell such Securities purchased under this Prospectus. This may affect the pricing of such Securities in the secondary market, the transparency and availability of trading prices, the liquidity of such Securities and the extent of issuer regulation. See “ Risk Factors ”.

Prospective investors should be aware that the purchase of Securities may have tax consequences that may not be fully described in this Prospectus or in any Prospectus Supplement, and should carefully review the tax discussion, if any, in the applicable Prospectus Supplement and in any event consult with a tax adviser.

An investment in the Securities is subject to a number of risks. See “ Risk Factors ” for a more complete discussion of these risks.

No underwriter has been involved in the preparation of this Prospectus or performed any review of the contents hereof.

The Company is not making an offer of the Securities in any jurisdiction where such offer is not permitted.

All dollar amounts in this Prospectus are in Canadian dollars, unless otherwise indicated. See “ Currency Presentation and Exchange Rate Information ”.

The Company’s head office address is Suite 1800 – 925 West Georgia Street, Vancouver, British Columbia V6C 3L2, and its registered office is located at Suite 2500 – 666 Burrard Street, Vancouver, British Columbia V6C 2X8.

Dr. Christopher Osterman is a director of the Company who resides outside of Canada, and has appointed Bennett Jones LLP at Suite 2500 – 666 Burrard Street, Vancouver, British Columbia V6C 2X8, as his agent for service of process in Canada. Prospective investors are advised that it may not be possible for investors to enforce judgements obtained in Canada against any person or company that is incorporated, continued or otherwise organized under the laws of a foreign jurisdiction or resides outside of Canada, even if the party has appointed an agent for service of process.

Mr. Keith Neumeyer is a director and the Chairman of the Board of Directors of the Company who resides outside of Canada and has appointed Bennett Jones LLP at Suite 2500 – 666 Burrard Street, Vancouver, British Columbia V6C 2X8, as his agent for service of process in Canada. Prospective investors are advised that it may not be possible for investors to enforce judgements obtained in Canada against any person or company that is incorporated, continued or otherwise organized under the laws of a foreign jurisdiction or resides outside of Canada, even if the party has appointed an agent for service of process.

No person is authorized by the Company to provide any information or to make any representation other than as contained in this Prospectus in connection with the issue and sale of the Securities offered hereunder. Prospective investors should rely only on the information contained or incorporated by reference in this Prospectus and any applicable Prospectus Supplement in connection with an investment in Securities. Prospective investors should assume that the information appearing in this Prospectus or any Prospectus Supplement is accurate only as of the date on the front of those documents and that information contained in any document incorporated by reference is accurate only as of the date of that document unless specified otherwise. The Company’s business, financial condition, results of operations and prospects may have changed since those dates.

Market data and certain industry forecasts used in this Prospectus or any applicable Prospectus Supplement and the documents incorporated by reference herein or therein were obtained from market research, publicly available information and industry publications. The Company believes that these sources are generally reliable, but the accuracy and completeness of the information is not guaranteed. The Company has not independently verified this information and does not make any representation as to the accuracy of this information.

References to “the Company”, “we” or “us” include direct and indirect subsidiaries of the Company, where applicable.

CAUTIONARY STATEMENTS REGARDING FORWARD-LOOKING INFORMATION ......6 CAUTIONARY NOTE TO US INVESTORS ................................................................................7 FINANCIAL INFORMATION .......................................................................................................8 CURRENCY PRESENTATION AND EXCHANGE RATE INFORMATION ............................8 DOCUMENTS INCORPORATED BY REFERENCE ..................................................................8 DOCUMENTS FILED AS PART OF THE REGISTRATION STATEMENT ...........................10 AVAILABLE INFORMATION ....................................................................................................10 SUMMARY OF THE BUSINESS ................................................................................................11 USE OF PROCEEDS ....................................................................................................................12 CONSOLIDATED CAPITALIZATION OF THE COMPANY ...................................................12 PLAN OF DISTRIBUTION ..........................................................................................................13 DESCRIPTION OF SECURITIES ................................................................................................14 PRIOR SALES...............................................................................................................................17 TRADING PRICE AND VOLUME .............................................................................................18 CERTAIN FEDERAL INCOME TAX CONSIDERATIONS......................................................19 RISK FACTORS ...........................................................................................................................19 EXEMPTION FROM NATIONAL INSTRUMENT 44-102 ..........................................................20 LEGAL MATTERS .......................................................................................................................20 INTERESTS OF EXPERTS ..........................................................................................................21 AUDITOR, TRANSFER AGENT AND REGISTRAR ................................................................22 ENFORCEABILITY OF CERTAIN CIVIL LIABILITIES .........................................................22 CONTRACTUAL RIGHTS OF RESCISSION ............................................................................22 GLOSSARY OF MINING TERMS ..............................................................................................23 STATUTORY RIGHTS OF WITHDRAWAL AND RESCISSION ............................................24 CERTIFICATE OF FIRST MINING GOLD CORP.....................................................................25

CAUTIONARY STATEMENTS REGARDING FORWARD-LOOKING INFORMATION

Certain statements contained in this Prospectus and the documents incorporated by reference herein constitute forward-looking information or forward-looking statements under applicable securities laws (collectively, “ forwardlooking statements ”). These statements relate to future events or future performance, business prospects or opportunities of the Company. All statements other than statements of historical fact may be forward-looking statements. Any statements that express or involve discussions with respect to predictions, expectations, beliefs, plans, projections, objectives, assumptions or future events or performance (often, but not always, using words or phrases such as “seek”, “anticipate”, “plan”, “continue”, “estimate”, “expect”, “may”, “will”, “project”, “predict”, “forecast”, “potential”, “targeting”, “intend”, “could”, “might”, “should”, “believe” and similar expressions) are not statements of historical fact and may be “forward-looking statements”.

Examples of forward-looking statements in the Prospectus and the documents incorporated by reference herein include, but are not limited to: statements regarding future acquisitions of mineral properties; statements relating to the Company’s belief that the jurisdictions in eastern Canada in which the Company holds mineral properties are mining friendly; the Company’s objective of becoming a mid-tier gold producer; the Company’s strategy of de-risking material assets through exploration, drilling, calculating resource estimates, conducting economic studies and other activities; the Company’s plan to retain a residual interest in projects in the form of royalties, metal streams, minority interests or equity positions; statements relating to the Company’s vision and strategy; the Company’s intention to eventually pay a dividend to its shareholders; the Company's intention to utilize its management team's expertise to successfully permit and construct producing mines at its material assets; statements relating to the criteria the Company will use when assessing potential acquisitions; the Company’s belief that they will continue to be able to locate and retain professionals with the necessary specialized skills and knowledge; statements regarding the Company's intention and ability to select, acquire and bring to production suitable properties or prospects for mineral exploration and production; the Company’s ability to raise the capital necessary to fund its operations and the potential development of its properties; the Company's ability to obtain the resources to conduct exploration and development activities on its properties; the Company’s belief that the policies and procedures implemented by the executive management team of the Company provide a safe working environment for all of its employees, consultants, contractors and stakeholders; statements regarding shifts in gold demand; the Company’s intention to continue to make expenditures to ensure compliance with applicable laws and regulations; the Company’s ability to work with the various Indigenous communities in relation to the development of the Company’s projects; the Company’s intention to construct a low-profile, resource access road to connect the Hope Brook Project to the Burgeo Highway or Highway 480; the Company’s intentions and expectations regarding exploration at any of its mineral properties; forecasts relating to mining, development and other activities at the Company’s operations; statements regarding potential increases in the ultimate recovery of gold and silver from its properties, including the Springpole Project; forecasts relating to market developments and trends in global supply and demand for gold; future royalty and tax payments and rates; future work on the Company’s non-material properties; the Company's intention to complete an updated preliminary economic assessment for the Springpole Project; the Company's intention to advance the permitting process at the Springpole Project, including the proposed submission of an environmental impact statement and the timing of such submission; the Company's intention to continue step-out drilling of the Miller prospect at the Goldlund Project and the goal of establishing an initial resource estimate for such prospect; and the Company’s mineral reserve and mineral resource estimates.

the Company may lose its interest in certain projects if it fails to make certain required payments or minimum expenditures; the Company may be unable to enforce their legal rights under their existing agreements, permits or licences, or may be subject to litigation or arbitration that has an adverse outcome; accidents or equipment breakdowns may occur; cyclical nature of the mining industry; there may be changes to government regulations or policies, including tax and trade laws and policies; the Company may be adversely affected by changes in foreign currency exchange rates, interest rates or tax rates; the Company’s estimates of production, purchases, costs, decommissioning or reclamation expenses, or their tax expense estimates, may prove to be inaccurate; natural phenomena, including inclement weather, fire, flood and earthquakes; the Company’s operations may be disrupted due to problems with its own or customer facilities, the unavailability of reagents or equipment, equipment failure, lack of tailings capacity, labour shortages, ground movements, transportation disruptions or accidents or other exploration and development risk; future sales by existing shareholders could reduce the market price of the Common Shares; the Company may be adversely affected by currency fluctuations, volatility in securities markets and volatility in mineral prices; the Company’s broad discretion relating to the use of proceeds raised hereunder; the absence of a market through which the Securities, other than the Common Shares, may be sold, and additional factors described under the heading “ Risk Factors ” in this Prospectus, under the heading “ Risks That Can Affect Our Business ” in the Company’s annual information form for the year ended December 31, 2018 and under the section “ Risks and Uncertainties ” in the Company’s management discussion and analysis for the year ended December 31, 2018.

The Company believes that the expectations reflected in any forward-looking statements are reasonable, but no assurance can be given that these expectations will prove to be correct and such forward-looking statements included in, or incorporated by reference into, this Prospectus should not be unduly relied upon. These statements speak only as of the date of this Prospectus. The Company does not intend, and does not assume any obligation, to update these forward-looking statements, except as required by applicable laws. Actual results may differ materially from those expressed or implied by such forward-looking statements.

CAUTIONARY NOTE TO US INVESTORS

This Prospectus, including the documents incorporated by reference herein, has been prepared in accordance with the requirements of the securities laws in effect in Canada which differ from the requirements of United States securities laws. All mining terms used herein but not otherwise defined have the meanings set forth in National Instrument 43101 Standards of Disclosure for Mineral Projects (“ NI 43-101 ”). The definitions of Proven and Probable Reserves (“Mineral Reserves” or “Reserves”) used in NI 43-101 differ from the definitions in the SEC Industry Guide 7. Under SEC Industry Guide 7 standards, a “final” or “bankable” feasibility study is required to report reserves, the three year historical average price is used in any reserve or cash flow analysis to designate reserves and the primary environmental analysis or report must be filed with the appropriate governmental authority.

In addition, the terms “Mineral Resource”, “Measured Mineral Resource”, “Indicated Mineral Resource” and “Inferred Mineral Resource” are defined in and required to be disclosed by NI 43-101; however, these terms are not defined terms under SEC Industry Guide 7 and normally are not permitted to be used in reports and registration statements filed with the SEC. Investors are cautioned not to assume that any part or all of the mineral deposits in these categories will ever be converted into reserves. “Inferred Mineral Resources” have a great amount of uncertainty as to their existence, and great uncertainty as to their economic and legal feasibility. It cannot be assumed that all or any part of an Inferred Mineral Resource will ever be upgraded to a higher category. Under Canadian securities laws, estimates of Inferred Mineral Resources may not form the basis of feasibility or prefeasibility studies, except in certain specific cases. Additionally, disclosure of “contained ounces” in a resource is permitted disclosure under Canadian securities laws, however, the SEC normally only permits issuers to report mineralization that does not constitute “reserves” by SEC standards as in place tonnage and grade without reference to unit measurements.

Accordingly, information contained in this Prospectus and the documents incorporated by reference herein containing descriptions of the Company’s mineral deposits may not be comparable to similar information made public by U.S. companies subject to the reporting and disclosure requirements of United States federal securities laws and the rules and regulations thereunder.

See “ Glossary of Mining Terms ” in this Prospectus for a description of certain of the mining terms used in this Prospectus, in any Prospectus Supplement and in the documents incorporated by reference.

FINANCIAL INFORMATION

Unless otherwise indicated, all financial information included and incorporated by reference in this Prospectus is determined using IFRS, which differs from United States generally accepted accounting principles.

CURRENCY PRESENTATION AND EXCHANGE RATE INFORMATION

The financial statements of the Company incorporated by reference in this Prospectus are reported in Canadian dollars. In this Prospectus, all dollar amounts referenced, unless otherwise indicated, are expressed in Canadian dollars and are referred to as “$” or “C$”. United States dollars are referred to as “US$”. The high, low and closing exchange rates for United States dollars in terms of the Canadian dollar for each of the indicated periods, as quoted by the Bank of Canada, were as follows:

High…………. Low…………. Closing……....	Year ended December 31 (US$)
	May 31, 2019 2018 2017 2016 0.7637 0.8138 0.8245 0.7972 0.7353 0.7330 0.7276 0.6854 0.7393 0.7330 0.7971 0.7448

On June 21, 2019, the exchange rate for United States dollars in terms of the Canadian dollar, as quoted by the Bank of Canada, was C$1.00 = US$0.7569.

DOCUMENTS INCORPORATED BY REFERENCE

Information has been incorporated by reference in this Prospectus from documents filed with securities commissions or similar authorities in each of the provinces of Canada (the “ Qualifying Provinces ”). Copies of the documents incorporated herein by reference or a copy of the Company’s permanent information record may be obtained on request without charge from the Company’s General Counsel & Corporate Secretary at Suite 1800 – 925 West Georgia Street, Vancouver, British Columbia V6C 3L2, or by accessing the disclosure documents available electronically in Canada on the System for Electronic Document Analysis and Retrieval (SEDAR), which can be accessed at www.sedar.com or in the United States through EDGAR at the website of the SEC at www.sec.gov. The filings of the Company through SEDAR and EDGAR are not incorporated by reference in this Prospectus except as specifically set out herein.

As at the date hereof, the following documents of the Company, filed with the securities commissions or similar authorities in each of the Qualifying Provinces, are specifically incorporated by reference into and form an integral part of this Prospectus, provided that such documents are not incorporated by reference to the extent that their contents are modified or superseded by a statement contained in this Prospectus or in any other subsequently filed document that is also incorporated by reference in the Prospectus, as further described below:

(a) the annual information form of the Company dated March 29, 2019 for the year ended December 31, 2018, filed on SEDAR on April 1, 2019;
(b) the audited consolidated financial statements of the Company as at and for the years ended December 31, 2018 and December 31, 2017, together with the notes thereto and the independent auditor’s report thereon, filed on SEDAR on April 1, 2019;
(c) the management’s discussion and analysis of the Company for the year ended December 31, 2018, filed on SEDAR on April 1, 2019;
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(d) the unaudited condensed interim consolidated financial statements of the Company as at and for the period ended March 31, 2019 and March 31, 2018, together with the notes thereto, filed on SEDAR on May 15, 2019;
(e) the management’s discussion and analysis of the Company for the period ended March 31, 2019, filed on SEDAR on May 15, 2019;
(f) the management information circular of the Company dated May 15, 2019 distributed in connection with the Company’s annual general meeting of shareholders to be held on June 25, 2019, filed on SEDAR on May 17, 2019; and
(g) the material change report of the Company dated May 24, 2019 in connection with the closing of a non-brokered private placement offering by the Company (the “ Private Placement ”), filed on SEDAR on May 24, 2019.

Any document of the type referred to in the preceding paragraph (excluding confidential material change reports), and all other documents of the type required to be incorporated by reference in a short form prospectus by National Instrument 44-101 Short Form Prospectus Distributions of the Canadian Securities Administrators, filed by the Company with a securities commission or similar regulatory authority in Canada after the date of this Prospectus and prior to the termination of any offering of Securities hereunder shall be deemed to be incorporated by reference into this Prospectus. In addition, to the extent that any document or information incorporated by reference into this Prospectus is included in any report on Form 6-K, Form 40-F, Form 20-F, Form 10-K, Form 10-Q or Form 8-K (or any respective successor form) that is filed with or furnished by the Company to the SEC after the date of this Prospectus, that document or information shall be deemed to be incorporated by reference as an exhibit to the Registration Statement (as defined below) of which this Prospectus forms a part (in the case of Form 6-K and Form 8-K, if and to the extent set forth therein). The Company may also incorporate other information filed with or furnished to the SEC under the United States Securities Exchange Act of 1934, as amended (the “Exchange Act”), provided that information included in any report on Form 6-K or Form 8-K shall be so deemed to be incorporated by reference only if and to the extent expressly provided in such Form 6-K or Form 8-K.

Any statement contained in this Prospectus or in a document incorporated or deemed to be incorporated by reference in this Prospectus shall be deemed to be modified or superseded, for purposes of this Prospectus, to the extent that a statement contained herein or in any other subsequently filed document that also is or is deemed to be incorporated by reference in this Prospectus modifies or supersedes that statement. Any such modifying or superseding statement need not state that it has modified or superseded a prior statement or include any other information set forth in the document that it modifies or supersedes. The making of a modifying or superseding statement shall not be deemed an admission for any purposes that the modified or superseded statement, when made, constituted a misrepresentation, an untrue statement of a material fact or an omission to state a material fact that is required to be stated or that is necessary to make a statement not misleading in light of the circumstances in which it was made. Any statement so modified or superseded shall not be considered in its unmodified or superseded form to constitute part of this Prospectus; rather only such statement as so modified or superseded shall be considered to constitute part of this Prospectus.

Upon a new annual information form and related annual audited consolidated financial statements and management’s discussion and analysis being filed by the Company with, and where required, accepted by, the applicable securities regulatory authorities during the term of this Prospectus: (i) the previous annual information form, the previous annual audited consolidated financial statements and related management’s discussion and analysis; (ii) all interim consolidated financial statements and related management’s discussion and analysis, all material change reports and all business acquisition reports filed by the Company prior to the commencement of the Company’s financial year in respect of which the new annual information form is filed; and (iii) any business acquisition report for acquisitions completed since the beginning of the financial year in respect of which the new annual information form is filed (unless such report is incorporated by reference into the current annual information form or less than nine months of the acquired business or related businesses operations are incorporated into the Company’s current annual

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audited consolidated financial statements) shall be deemed no longer to be incorporated by reference into this Prospectus for purposes of future offers and sales of Securities hereunder.

Upon new interim consolidated financial statements and related management’s discussion and analysis being filed by the Company with the applicable securities regulatory authorities in Canada during the term of this Prospectus, all interim consolidated financial statements and related management’s discussion and analysis filed prior to the new interim consolidated financial statements shall be deemed no longer to be incorporated by reference into this Prospectus for purposes of future offers and sales of Securities hereunder.

Upon a new information circular relating to an annual meeting of shareholders being filed by the Company with applicable securities regulatory authorities in Canada subsequent to the date of this Prospectus and prior to the date on which this Prospectus ceases to be effective, the information circular for the preceding annual meeting of shareholders and any other information circular filed by the Company prior to the commencement of the Company’s financial year in respect of which the new annual information form is filed shall be deemed no longer to be incorporated by reference into this Prospectus for purposes of offers and sales of Securities under this Prospectus.

A Prospectus Supplement containing the specific terms of any Securities offered thereunder will be delivered to purchasers of such Securities together with this Prospectus to the extent required under applicable securities laws except in cases where an exemption from such delivery has been obtained and will be deemed to be incorporated by reference into this Prospectus as of the date of such Prospectus Supplement solely for the purposes of the Securities offered thereunder.

In addition, certain marketing materials (as that term is defined in applicable Canadian securities legislation) may be used in connection with a distribution of Securities under this Prospectus and the applicable Prospectus Supplement(s). Any “template version” of “marketing materials” (as those terms are defined in applicable Canadian securities legislation) pertaining to a distribution of Securities, and filed by the Company after the date of the Prospectus Supplement for the distribution and before termination of the distribution of such Securities, will be deemed to be incorporated by reference in that Prospectus Supplement for the purposes of the distribution of Securities to which the Prospectus Supplement pertains.

The Company has not provided or otherwise authorized any other person to provide investors with information other than as contained or incorporated by reference in this Prospectus or any Prospectus Supplement. If an investor is provided with different or inconsistent information, he or she should not rely on it.

DOCUMENTS FILED AS PART OF THE REGISTRATION STATEMENT

The following documents have been, or will be, filed with the SEC as part of the Registration Statement (as defined below) of which this Prospectus forms a part: (1) the documents listed under “ Documents Incorporated by Reference ”; (2) the consent of PricewaterhouseCoopers LLP; (3) powers of attorney from certain of the Company’s directors and officers; and (4) the consents of the “qualified persons” referred to in this Prospectus under “ Interests of Experts ”. A copy of the form of any applicable warrant agreement or subscription receipt agreement will be filed by post-effective amendment or by incorporation by reference to documents filed or furnished with the SEC under the Exchange Act.

AVAILABLE INFORMATION

The Company is subject to the information reporting requirements of the Exchange Act and applicable Canadian requirements and, in accordance therewith, files reports and other information with the SEC and with securities regulatory authorities in Canada. Under the multi-jurisdictional disclosure system adopted by the United States and Canada, such reports and other information may generally be prepared in accordance with the disclosure requirements of Canada, which requirements are different from those of the United States. As a foreign private issuer, the Company is exempt from the rules under the Exchange Act prescribing the furnishing and content of proxy statements, and the Company’s officers, directors and principal shareholders are exempt from the reporting and short-swing profit recovery provisions contained in Section 16 of the Exchange Act. Prospective investors may read and download any public document that the Company has filed with the securities commission or similar regulatory authority in each of the provinces of Canada on SEDAR at www.sedar.com. The reports and other information filed and furnished by the

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Company with the SEC can be inspected on the SEC’s website at www.sec.gov. Reports and other information filed by the Company with, or furnished to, the SEC may also be inspected and copied for a fee at the public reference facilities maintained by the SEC at 100 F Street, N.E., Washington, D.C., 20549.

The Company has filed with the SEC a registration statement on Form F-10 (the “ Registration Statement ”) under the United States Securities Act of 1933, as amended (the “ U.S. Securities Act ”), with respect to the Securities. This Prospectus, which forms part of the Registration Statement, does not contain all of the information set forth in the Registration Statement, certain parts of which are contained in the exhibits to the Registration Statement as permitted by the rules and regulations of the SEC. See “ Documents Filed as Part of the Registration Statement ”. For further information with respect to the Company and the Securities, reference is made to the Registration Statement and the exhibits thereto. Statements contained in or incorporated by reference into this Prospectus about the contents of any contract, agreement or other document are not necessarily complete and, in each instance, reference is made to the copy of the document filed as an exhibit to the Registration Statement for a complete description of the matter involved. Each such statement is qualified in its entirety by such reference. Each time the Company sells Securities under the Registration Statement, it will provide a Prospectus Supplement that will contain specific information about the terms of that offering. The Prospectus Supplement may also add, update or change information contained in this Prospectus.

SUMMARY OF THE BUSINESS

First Mining is an emerging mineral development company with a diversified portfolio of gold projects in North America. The Company’s vision is to advance its material assets towards a construction decision and, ultimately, to production, while continuing to assess mineral asset acquisition targets on an ongoing basis.

Since initially listing on the TSX Venture Exchange in April 2015, and on the Exchange in June 2017, the Company has completed eight acquisitions and, as a result, has accumulated approximately 7.3 million ounces of gold Measured and Indicated Resources and approximately 3.7 million ounces of gold Inferred Resources in mining friendly jurisdictions in eastern Canada. The following table highlights the Company’s material projects:

Date Acquired	Project	Location
June 16, 2016	Goldlund Gold Project	Northern Ontario, Canada
June 9, 2016	Cameron Gold Project	Northern Ontario, Canada
November 16, 2015	Pickle Crow Gold Project	Northern Ontario, Canada
November 13, 2015	Springpole Gold Project	Northern Ontario, Canada
July 7, 2015	Hope Brook Gold Project	Newfoundland, Canada

Recent Developments

On April 2, 2019, the Company announced the appointment of Mal Karwowska as the Company’s Vice President, Corporate Development and Investor Relations, effective April 1, 2019.

On April 24, 2019, the Company announced the appointment of Ken Engquist as the Company’s Chief Operating Officer, effective April 29, 2019.

On May 16, 2019, the Company announced the closing of the Private Placement, pursuant to which the Company issued 20,412,995 units (“ Units ”) at a price of $0.27 per Unit, and 5,277,777 flow-through units (“ FT Units ”) at a price of $0.36 per FT Unit, for aggregate gross proceeds of $7,411,508. Each Unit consisted of one Common Share and one-half of one Common Share purchase warrant (each whole Common Share purchase warrant, a “ Warrant ”), with each such Warrant exercisable to acquire one Common Share at a price of $0.40 per Common Share for a period of three years following the closing date of the Private Placement. Each FT Unit consisted of one Common Share that

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qualifies as a “flow-through share” for the purposes of the Income Tax Act (Canada) and one-half of one Warrant, with each whole Warrant exercisable by the holder on the same terms as those Warrants issued as part of the Units.

On June 12, 2019, the Company announced the commencement of work programs for the Company's Canadian gold assets with a primary focus on the Springpole Project and the Goldlund Project. The intention for the Springpole Project is to complete an updated preliminary economic assessment to incorporate metallurgical work completed in 2018 and 2019 as well as to advance the permitting process through the provincial and federal environmental assessment processes with a goal of submitting a final environmental impact statement in early 2021. At the Goldlund Gold Project, the Company intends to continue step-out drilling at the Miller prospect with the intention of establishing an initial resource estimate and to define the broader regional potential of the project.

More detailed information regarding the business of the Company, its operations and its assets can be found in the Company’s annual information form and other documents which are incorporated in this Prospectus by reference. See “ Documents Incorporated by Reference ”.

USE OF PROCEEDS

The use of proceeds from the sale of Securities will be described in the applicable Prospectus Supplement relating to a specific offering and sale of Securities. Among other potential uses, the Company may use the net proceeds from the sale of Securities for general corporate purposes, including funding ongoing operations and/or working capital requirements, to repay indebtedness outstanding from time to time, capital projects and potential future acquisitions.

The Company had negative cash flow from operating activities for the financial year ended December 31, 2018. To the extent that the Company has negative cash flow from operating activities in future periods, the Company may need to use a portion of the proceeds from any offering to fund such negative cash flow. See “ Risk Factors – Negative Cash Flow from Operating Activities .”

Management of the Company will retain broad discretion in allocating the net proceeds of any offering of Securities under this Prospectus and the Company’s actual use of the net proceeds will vary depending on the availability and suitability of investment opportunities and its operating and capital needs from time to time. All expenses relating to an offering of Securities and any compensation paid to underwriting dealers or agents as the case may be, will be paid out of the proceeds from the sale of Securities, unless otherwise stated in the applicable Prospectus Supplement.

The Company may, from time to time, issue securities (including Securities) other than pursuant to this Prospectus.

CONSOLIDATED CAPITALIZATION OF THE COMPANY

The following table summarizes changes in the consolidated capitalization of the Company since the date of the Company’s audited consolidated financial statements as at and for the year ended December 31, 2018:

Description	Authorized	Outstanding as at December 31, 2018	Outstanding as at the date of the Prospectus
Common Shares	Unlimited	558,316,916	584,221,888(1)
Warrants	N/A	20,116,855	32,747,998(1)

Note:

(1) See “ Prior Sales ”.
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PLAN OF DISTRIBUTION

The Company may from time to time during the 25-month period that this Prospectus, including any amendments hereto, remains valid, offer for sale and issue up to an aggregate of $100,000,000 in Securities hereunder.

The Company may offer and sell the Securities to or through underwriters or dealers purchasing as principals, and may also sell directly to one or more purchasers or through agents or pursuant to applicable statutory exemptions. The Prospectus Supplement relating to a particular offering of Securities will identify each underwriter, dealer or agent, as the case may be, engaged by the Company in connection with the offering and sale of the Securities, and will set forth the terms of the offering of such Securities, including, to the extent applicable, any fees, discounts or any other compensation payable to underwriters, dealers or agents in connection with the offering, the method of distribution of the Securities, the initial issue price, the proceeds that the Company will receive and any other material terms of the plan of distribution. Any initial offering price and discounts, concessions or commissions allowed or reallowed or paid to dealers may be changed from time to time.

In addition, the Securities may be offered and issued in consideration for the acquisition of other businesses, assets or securities by the Company or one of its subsidiaries. The consideration for any such acquisition may consist of the Securities separately, a combination of Securities or any combination of, among other things, Securities, cash and assumption of liabilities.

The Securities may be sold, from time to time in one or more transactions at a fixed price or prices or at prices which may be changed or at market prices prevailing at the time of sale, at prices related to such prevailing prices or at negotiated prices, including sales in transactions that are deemed to be “at-the-market distributions” as defined in NI 44-102, including sales made directly on the Exchange or other existing trading markets for the Common Shares. The price at which the Securities will be offered and sold may vary as between purchasers and during the period of distribution of the applicable Securities. If, in connection with the offering of Securities at a fixed price or prices, the underwriters, dealers or agents have made a bona fide effort to sell all of the Securities at the initial offering price fixed in the applicable Prospectus Supplement, the public offering price may be decreased and thereafter further changed, from time to time, to an amount not greater than the initial offering price fixed in such Prospectus Supplement, in which case the compensation realized by the underwriters, dealers or agents will be decreased by the amount that the aggregate price paid by purchasers for the Securities is less than the gross proceeds paid by the underwriters, dealers or agents to the Company.

In connection with the sale of the Securities, underwriters, dealers or agents may receive compensation from the Company or from other parties, including in the form of underwriters’, dealers’ or agents’ fees, commissions or concessions. Underwriters, dealers and agents that participate in the distribution of the Securities may be deemed to be underwriters for the purposes of applicable Canadian securities legislation and any such compensation received by them from the Company and any profit on the resale of the Securities by them may be deemed to be underwriting commissions.

In connection with any offering of Securities, except as otherwise set out in a Prospectus Supplement relating to a particular offering of Securities and other than in relation to an “at-the-market” distribution, the underwriters, dealers or agents, as the case may be, may over-allot or effect transactions intended to fix, stabilize, maintain or otherwise affect the market price of the Securities at a level other than those which otherwise might prevail on the open market. Such transactions may be commenced, interrupted or discontinued at any time.

Underwriters, dealers or agents who participate in the distribution of the Securities may be entitled, under agreements to be entered into with the Company, to indemnification by the Company against certain liabilities, including liabilities under the U.S. Securities Act and Canadian securities legislation, or to contribution with respect to payments which such underwriters, dealers or agents may be required to make in respect thereof. Such underwriters, dealers and agents may be customers of, engage in transactions with, or perform services for, the Company in the ordinary course of business.

Unless otherwise specified in the applicable Prospectus Supplement, each series or issue of Securities (other than Common Shares) will be a new issue of Securities with no established trading market. Accordingly, there is currently

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no market through which the Securities (other than Common Shares) may be sold and purchasers may not be able to resell such Securities purchased under this Prospectus. This may affect the pricing of such Securities in the secondary market, the transparency and availability of trading prices, the liquidity of such Securities and the extent of issuer regulation. No assurances can be given that a market for trading in Securities (other than Common Shares) of any series or issue will develop or as to the liquidity of any such market, whether or not the Securities are listed on a securities exchange. See “ Risk Factors ”.

DESCRIPTION OF SECURITIES

The following is a brief summary of certain general terms and provisions of the Securities as at the date of this Prospectus. The summary does not purport to be complete and is indicative only. The specific terms of any Securities to be offered under this Prospectus, and the extent to which the general terms described in this Prospectus apply to such Securities, will be set forth in the applicable Prospectus Supplement. Moreover, a Prospectus Supplement relating to a particular offering of Securities may include terms pertaining to the Securities being offered thereunder that are not within the terms and parameters described in this Prospectus.

Description of Common Shares

The following is a brief summary of the material attributes of the Common Shares. This summary does not purport to be complete.

The holders of Common Shares are entitled to one vote per share at all meetings of shareholders of the Company except separate meetings of the holders of another class or series of shares of the Company. Subject to the preferences accorded to holders of any class of shares of the Company ranking senior to or equal with the Common Shares, the Common Shares are entitled to dividends, if and when declared by the Company’s Board of Directors, and to the distribution of the residual assets of the Company in the event of the liquidation, dissolution or winding-up of the Company.

Holders of our Common Shares have no pre-emptive, redemption, purchase or conversion rights attaching to their shares, and the Common Shares, when fully paid, will not be liable to further call or assessment. No other class of shares may be created without the approval of the holders of the Common Shares. There are no provisions discriminating against any existing or prospective holder of the Common Shares as a result of such shareholder owning a substantial number of Common Shares. In addition, non-residents of Canada who hold Common Shares have the same rights as shareholders who are residents of Canada.

Common Shares offered hereunder may be “flow-through shares” within the meaning of the Income Tax Act (Canada). The particular terms and provisions of any such offerings by any Prospectus Supplement will be described in such Prospectus Supplement. Common Shares may be offered separately or together with other Securities.

Description of Preferred Shares

The following is a brief summary of certain general terms and provisions of the Preferred Shares that may be offered pursuant to this Prospectus. This summary does not purport to be complete. The particular terms and provisions of the Preferred Shares as may be offered pursuant to this Prospectus will be set forth in the applicable Prospectus Supplement pertaining to such offering of Preferred Shares, and the extent to which the general terms and provisions described below may apply to such Preferred Shares will be described in the applicable Prospectus Supplement.

The Preferred Shares are issuable in series. The Preferred Shares of each series rank in parity with the Preferred Shares of every other series with respect to dividends and return of capital and are entitled to a preference over the Common Shares and any other shares ranking junior to the Preferred Shares with respect to priority in the payment of dividends and the distribution of assets in the event of the liquidation, dissolution or winding-up of the Company.

The Company’s Board of Directors is empowered to fix the number of Preferred Shares and the rights to be attached to the Preferred Shares of each series, including the amount of dividends and any conversion, voting and redemption

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rights. Subject to the Company’s Articles and applicable law, the Preferred Shares as a class are not entitled to receive notice of or attend or vote at meetings of the Company’s shareholders.

Description of Warrants

The following is a brief summary of certain general terms and provisions of the Warrants that may be offered pursuant to this Prospectus. This summary does not purport to be complete. The particular terms and provisions of the Warrants as may be offered pursuant to this Prospectus will be set forth in the applicable Prospectus Supplement pertaining to such offering of Warrants, and the extent to which the general terms and provisions described below may apply to such Warrants will be described in the applicable Prospectus Supplement.

Warrants may be offered separately or together with other Securities, as the case may be. Each series of Warrants may be issued under a separate warrant indenture or warrant agency agreement to be entered into between the Company and one or more banks or trust companies acting as Warrant agent or may be issued as stand-alone contracts. The applicable Prospectus Supplement will include details of the Warrant agreements, if any, governing the Warrants being offered. The Warrant agent, if any, will be expected to act solely as the agent of the Company and will not assume a relationship of agency with any holders of Warrant certificates or beneficial owners of Warrants. A copy of any warrant indenture or any warrant agency agreement relating to an offering of Warrants will be filed by the Company with the relevant securities regulatory authorities in Canada after it has been entered into by the Company.

Each applicable Prospectus Supplement will set forth the terms and other information with respect to the Warrants being offered thereby, which may include, without limitation, the following (where applicable):

the designation of the Warrants;
the aggregate number of Warrants offered and the offering price;
the designation, number and terms of the other Securities purchasable upon exercise of the Warrants, and procedures that will result in the adjustment of those numbers;
the exercise price of the Warrants;
the dates or periods during which the Warrants are exercisable including any “early termination” provisions;
the designation, number and terms of any Securities with which the Warrants are issued;
if the Warrants are issued as a unit with another Security, the date on and after which the Warrants and the other Security will be separately transferable;
whether such Warrants are to be issued in registered form, “book-entry only” form, bearer form or in the form of temporary or permanent global securities and the basis of exchange, transfer and ownership thereof;
any minimum or maximum amount of Warrants that may be exercised at any one time;
whether such Warrants will be listed on any securities exchange;
any terms, procedures and limitations relating to the transferability, exchange or exercise of the Warrants;
certain material Canadian tax consequences of owning the Warrants; and
any other material terms and conditions of the Warrants.
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Description of Subscription Receipts

The following is a brief summary of certain general terms and provisions of the Subscription Receipts that may be offered pursuant to this Prospectus. This summary does not purport to be complete. The particular terms and provisions of the Subscription Receipts as may be offered pursuant to this Prospectus will be set forth in the applicable Prospectus Supplement pertaining to such offering of Subscription Receipts, and the extent to which the general terms and provisions described below may apply to such Subscription Receipts will be described in the applicable Prospectus Supplement.

Subscription Receipts may be offered separately or together with other Securities, as the case may be. The Subscription Receipts may be issued under a subscription receipt agreement. The applicable Prospectus Supplement will include details of the subscription receipt agreement, if any, governing the Subscription Receipts being offered. The Company will file a copy of any subscription receipt agreement relating to an offering of Subscription Receipts with the relevant securities regulatory authorities in Canada after it has been entered into by the Company.

Each applicable Prospectus Supplement will set forth the terms and other information with respect to the Subscription Receipts being offered thereby, which may include, without limitation, the following (where applicable):

the number of Subscription Receipts;
the price at which the Subscription Receipts will be offered;
the terms, conditions and procedures for the conversion of the Subscription Receipts into other Securities;
the dates or periods during which the Subscription Receipts are convertible into other Securities;
the designation, number and terms of the other Securities that may be exchanged upon conversion of each Subscription Receipt;
the designation, number and terms of any other Securities with which the Subscription Receipts will be offered, if any, and the number of Subscription Receipts that will be offered with each Security;
whether such Subscription Receipts are to be issued in registered form, “book-entry only” form, bearer form or in the form of temporary or permanent global securities and the basis of exchange, transfer and ownership thereof;
terms applicable to the gross or net proceeds from the sale of the Subscription Receipts plus any interest earned thereon;
certain material Canadian tax consequences of owning the Subscription Receipts; and
any other material terms and conditions of the Subscription Receipts.

Description of Units

The following is a brief summary of certain general terms and provisions of the Units that may be offered pursuant to this Prospectus. This summary does not purport to be complete. The particular terms and provisions of the Units as may be offered pursuant to this Prospectus will be set forth in the applicable Prospectus Supplement pertaining to such offering of Units, and the extent to which the general terms and provisions described below may apply to such Units will be described in the applicable Prospectus Supplement.

Units may be offered separately or together with other Securities, as the case may be.

Each applicable Prospectus Supplement will set forth the terms and other information with respect to the Units being offered thereby, which may include, without limitation, the following (where applicable):

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the number of Units;
the price at which the Units will be offered;
the designation, number and terms of the Securities comprising the Units; whether the Units will be issued with any other Securities and, if so, the amount and terms of these Securities;
terms applicable to the gross or net proceeds from the sale of the Units plus any interest earned thereon;
the date on and after which the Securities comprising the Units will be separately transferable;
whether the Securities comprising the Units will be listed on any securities exchange;
whether such Units or the Securities comprising the Units are to be issued in registered form, “book-entry only” form, bearer form or in the form of temporary or permanent global securities and the basis of exchange, transfer and ownership thereof;
any terms, procedures and limitations relating to the transferability, exchange or exercise of the Units;
certain material Canadian tax consequences of owning the Units; and
any other material terms and conditions of the Units.

PRIOR SALES

Common Shares

The following table summarizes details of the Common Shares issued by the Company during the 12-month period prior to the date of this Prospectus:

	Weighted Average Price	Weighted Average Price
	Per Common	Share	Aggregate Number of
Date of Issuance	($)		Common Shares
November 13, 2018(1)	$	0.20	100,000
November 27, 2018(1)	$	0.18	274,000
April 2, 2019(2)	$	0.20	214,200
May 16, 2019(3)	$	0.27	20,412,995
May 16, 2019(3)	$	0.36	5,277,777
		TOTAL	26,750,272

Notes:

(1) Issued pursuant to the exercise of Options.
(2) Issued pursuant to the exercise of Warrants.
(3) Issued pursuant to the Private Placement.
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Options

The following table summarizes details of the stock options issued by the Company during the 12-month period prior to the date of this Prospectus:

	Number of	Exercise Price
Date of Grant	Options Granted	($)	Expiry Date
July 20, 2018	50,000	$0.425	July 20, 2023
October 16, 2018	1,400,000	$0.400	October 16, 2023
December 10, 2018	12,075,000	$0.400	December 10, 2023
January 7, 2019	5,000,000	$0.400	January 7, 2024
April 1, 2019	750,000	$0.400	April 1, 2024
April 29, 2019	2,000,000	$0.400	April 29, 2024

TRADING PRICE AND VOLUME

The Common Shares trade on the Exchange under the symbol “FF”. On June 21, 2019, being the last trading day prior to the date of this Prospectus, the closing price of the Common Shares on the Exchange was $0.205. The price range and trading volume of the Common Shares for each month from June 2018 to June 2019, as reported by the Exchange, are set out below:

Month June 1 – 21, 2019 May 2019 April 2019 March 2019 February 2019 January 2019 December 2018 November 2018 October 2018 September 2018 August 2018 July 2018 June 2018	High Low $0.27 $0.205 $0.320 $0.250 $0.360 $0.270 $0.410 $0.310 $0.390 $0.325 $0.395 $0.310 $0.265 $0.210 $0.300 $0.255 $0.385 $0.285 $0.370 $0.330 $0.435 $0.345 $0.450 $0.410 $0.495 $0.435	Total Volume
		54,455,977 8,671,170 5,908,800 9,068,200 5,622,000 19,972,000 16,631,200 8,843,500 10,143,800 12,576,200 11,097,300 11,417,100 13,693,300

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CERTAIN FEDERAL INCOME TAX CONSIDERATIONS

The applicable Prospectus Supplement may describe certain Canadian federal income tax consequences to an investor who is a non-resident of Canada or to an investor who is a resident of Canada of acquiring, owning and disposing of any of the Securities offered thereunder. The applicable Prospectus Supplement may also describe certain U.S. federal income tax consequences of the acquisition, ownership and disposition of any of the Securities offered thereunder by an initial investor who is subject to United States federal taxation. Investors should read the tax discussion in any Prospectus Supplement with respect to a particular offering and consult their own tax advisors with respect to their own particular circumstances.

RISK FACTORS

Before deciding to invest in any Securities, prospective purchasers of the Securities should consider carefully the risk factors and the other information contained and incorporated by reference in this Prospectus and the applicable Prospectus Supplement relating to a specific offering of Securities before purchasing the Securities. An investment in the Securities offered hereunder is speculative and involves a high degree of risk. Information regarding the risks affecting the Company and its business is provided in the documents incorporated by reference in this Prospectus, including in the Company’s most recent annual information form under the heading “ Risks That Can Affect Our Business ”. Additional risks and uncertainties not known to the Company or that management currently deems immaterial may also impair the Company’s business, financial condition, results of operations or prospects. See “ Documents Incorporated by Reference ”.

Negative Cash Flow from Operating Activities

The Company has not yet achieved positive operating cash flow, and the Company will continue to experience negative cash flow from operations in the foreseeable future. The Company has incurred net losses in the past and may incur losses in the future unless it can derive sufficient revenues from its business. Such future losses could have an adverse effect on the market price of the Company’s securities, which could cause investors to lose part or all of their investment.

No Assurance of Active or Liquid Market

There is no public market for the Preferred Shares, Warrants, Subscription Receipts, or Units and, unless otherwise specified in the applicable Prospectus Supplement, the Company does not intend to apply for listing of such Securities on any securities exchanges. If the Preferred Shares, Warrants, Subscription Receipts, or Units are traded after their initial issue, they may trade at a discount from their initial offering prices depending on prevailing interest rates (as applicable), the market for similar securities and other factors including general economic conditions and the Company’s financial condition. There can be no assurance as to the liquidity of the trading market for the Preferred Shares, Warrants, Subscription Receipts, or Units or that a trading market for these securities will develop.

Public Markets and Share Prices

The market price of the Common Shares and any other Securities offered hereunder that become listed and posted for trading on the Exchange or any other stock exchange could be subject to significant fluctuations in response to variations in the Company’s financial results or other factors. In addition, fluctuations in the stock market may adversely affect the market price of the Common Shares and any other Securities offered hereunder that become listed and posted for trading on the Exchange or any other stock exchange regardless of the financial performance of the Company. Securities markets have also experienced significant price and volume fluctuations from time to time. In

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some instances, these fluctuations have been unrelated or disproportionate to the financial performance of issuers. Market fluctuations may adversely impact the market price of the Common Shares and any other Securities offered hereunder that become listed and posted for trading on the Exchange or any other stock exchange. There can be no assurance of the price at which the Common Shares or any other Securities offered hereunder that become listed and posted for trading on the Exchange or any other stock exchange will trade.

Additional Issuances and Dilution

The Company may issue and sell additional securities of the Company to finance its operations or future acquisitions. The Company cannot predict the size of future issuances of securities of the Company or the effect, if any, that future issuances and sales of securities will have on the market price of any Securities of the Company issued and outstanding from time to time. Sales or issuances of substantial amounts of securities of the Company, or the perception that such sales could occur, may adversely affect prevailing market prices for securities of the Company issued and outstanding from time to time. With any additional sale or issuance of securities of the Company, holders will suffer dilution with respect to voting power and may experience dilution in the Company’s earnings per share. Moreover, this Prospectus may create a perceived risk of dilution resulting in downward pressure on the price of the Company’s issued and outstanding Common Shares, which could contribute to progressive declines in the prices of such securities.

The Company has Broad Discretion in the Use of the Net Proceeds from this Offering

Management of the Company will have broad discretion with respect to the application of net proceeds received by the Company from the sale of Securities under this Prospectus or a future Prospectus Supplement and may spend such proceeds in ways that do not improve the Company’s results of operations or enhance the value of the Common Shares or its other securities issued and outstanding from time to time. Any failure by management to apply these funds effectively could result in financial losses that could have a material adverse effect on the Company’s business or cause the price of the securities of the Company issued and outstanding from time to time to decline.

EXEMPTION FROM NATIONAL INSTRUMENT 44-102

Pursuant to a decision of the Autorité des marchés financiers dated May 27, 2019, the Company was granted a permanent exemption from the requirement to translate into French this Prospectus as well as the documents incorporated by reference therein and any Prospectus Supplement to be filed in relation to an “at-the-market” distribution. This exemption is granted on the condition that this Prospectus and any Prospectus Supplement (other than in relation to an “at-the-market” distribution) be translated into French if the Company offers Securities to Québec purchasers in connection with an offering other than in relation to an “at-the-market” distribution.

LEGAL MATTERS

Unless otherwise specified in a Prospectus Supplement relating to any Securities offered, certain legal matters in connection with the offering of Securities will be passed upon on behalf of the Company by its external legal counsel, Bennett Jones LLP as to Canadian legal matters and Dorsey & Whitney LLP, as to United States legal matters. In addition, certain legal matters in connection with any offering of Securities will be passed upon for any underwriters, dealers or agents by counsel to be designated at the time of the offering by such underwriters, dealers or agents, as the case may be.

Mr. Keith Neumeyer and Dr. Christopher Osterman, each a director of the Company, reside outside of Canada. Mr. Neumeyer and Dr. Osterman have appointed the following agent for service of process in Canada:

Name of Person Name and Address of Agent Keith Neumeyer Bennett Jones LLP 2500 Park Place 666 Burrard Street Vancouver, British Columbia V6C 2X8

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Christopher Osterman

Bennett Jones LLP 2500 Park Place 666 Burrard Street Vancouver, British Columbia V6C 2X8

Purchasers are advised that it may not be possible for investors to enforce judgments obtained in Canada against any person that resides outside of Canada, even if the person has appointed an agent for service of process

INTERESTS OF EXPERTS

All technical and scientific information discussed in this Prospectus, any Prospectus Supplement or any documents incorporated by reference herein, including mineral resource estimates for the Company’s material properties, and all technical and scientific information for the Company’s other non-material projects, has been reviewed and approved by Dr. Christopher Osterman, Ph.D., P.Geo., a director of the Company who is a qualified person for the purposes of NI 43-101.

The following individuals prepared the NI 43-101 technical report entitled “Preliminary Economic Assessment Update for the Springpole Gold Project, Ontario, Canada” dated October 16, 2017 with an effective date of June 6, 2017:

Dr. Gilles Arseneau, Ph.D., P.Geo., Associate Consultant (Geology), of SRK Consulting (Canada) Inc.;
Dr. Adrian Dance, Ph.D., P.Eng., Principal Consultant (Metallurgy), of SRK Consulting (Canada) Inc.;
Victor Munoz, P.Eng., M.Eng., Senior Consultant (Water Resources Engineering), of SRK Consulting (Canada) Inc.;
Grant Carlson, P.Eng., Senior Consultant (Mining), of SRK Consulting (Canada) Inc.;
Neil Winkelmann, FAusIMM, Principal Consultant (Mining), of SRK Consulting (Canada) Inc.;
Bruce Andrew Murphy, P.Eng., Principal Consultant (Geotechnical), of SRK Consulting (Canada) Inc.;
Michael Royle, M.App.Sci., P.Geo., Principal Consultant (Hydrogeology), of SRK Consulting (Canada) Inc.; and
Mark Liskowich, P.Geo., Principal Consultant (Environmental), of SRK Consulting (Canada) Inc.

Todd McCracken, P.Geo., Manager – Mining of WSP Canada Inc., prepared the NI 43-101 technical report entitled “Technical Report and Resource Estimation Update, Goldlund Gold Project, Sioux Lookout, Ontario” dated April 1, 2019 with an effective date of March 15, 2019.

Mark Drabble, B.App.Sci (Geology), MAIG, MAusIMM, and Kahan Cervoj, B.App.Sci (Geology), MAIG, MAusIMM, Principal Consultants of Optiro Pty Limited, prepared the NI 43-101 technical report entitled “Technical Report on the Cameron Gold Deposit, Ontario, Canada” with an effective date of January 17, 2017.

B. Terrence Hennessey, P.Geo., of Micon International Limited, prepared the NI 43-101 technical report entitled “An Updated Mineral Resource Estimate for the Pickle Crow Property, Patricia Mining Division, Northwestern Ontario, Canada” dated June 15, 2018 with an effective date of August 31, 2016.

Michael P. Cullen, M.Sc., P.Geo., of Mercator Geological Services Limited, prepared the NI 43-101 technical report entitled “2015 Mineral Resource Estimate Technical Report for the Hope Brook Gold Project, Newfoundland and Labrador, Canada” dated November 20, 2015 with an effective date of January 12, 2015.

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appointed or employed as a director, officer or employee of the Company or of any associate or affiliate of the Company, other than Dr. Christopher Osterman, a director of the Company.

The partners and associates of Bennett Jones LLP, as a group, hold beneficially, directly or indirectly, less than 1% of any class of the Corporation’s securities.

AUDITOR, TRANSFER AGENT AND REGISTRAR

The auditor of the Company is PricewaterhouseCoopers LLP, chartered professional accountants, who have audited the Company’s 2018 annual consolidated financial statements. PricewaterhouseCoopers LLP have confirmed they are independent within the meaning of the Chartered Professional Accountants of British Columbia Code of Professional Conduct and the rules of the Public Company Accounting Oversight Board (U.S.). They are located at Suite 1400 – 250 Howe Street, Vancouver, British Columbia V6C 3S7.

The transfer agent and registrar for the Common Shares is Computershare Trust Company of Canada at its principal transfer office in Vancouver, British Columbia.

ENFORCEABILITY OF CERTAIN CIVIL LIABILITIES

The Company is governed by the laws of British Columbia and its principal place of business is outside the United States. The majority of the directors and officers of the Company and the experts named under “ Interests of Experts ” herein are resident outside of the United States and a substantial portion of the Company’s assets and the assets of such persons are located outside of the United States. Consequently, it may be difficult for United States investors to effect service of process within the United States on the Company, its directors or officers or such experts, or to realize in the United States on judgments of courts of the United States predicated on civil liabilities under the U.S. Securities Act. Investors should not assume that Canadian courts would enforce judgments of United States courts obtained in actions against the Company or such persons predicated on the civil liability provisions of the United States federal securities laws or the securities or “blue sky” laws of any state within the United States or would enforce, in original actions, liabilities against the Company or such persons predicated on the United States federal securities or any such state securities or “blue sky” laws. A final judgment for a liquidated sum in favour of a private litigant granted by a United States court and predicated solely upon civil liability under United States federal securities laws would, subject to certain exceptions identified in the law of individual provinces of Canada, likely be enforceable in Canada if the United States court in which the judgment was obtained had a basis for jurisdiction in the matter that would be recognized by the domestic Canadian court for the same purposes. There is a significant risk that a given Canadian court may not have jurisdiction or may decline jurisdiction over a claim based solely upon United States federal securities law on application of the conflict of laws principles of the province in Canada in which the claim is brought .

The Company filed with the SEC, concurrently with the Registration Statement, an appointment of agent for service of process on Form F-X. Under the Form F-X, the Company appointed Puglisi & Associates, with an address at 850 Library Avenue, Suite 204, Newark, Delaware 19711, as its agent for service of process in the United States in connection with any investigation or administrative proceeding conducted by the SEC, and any civil suit or action brought against or involving the Company in a United States court arising out of or related to or concerning the offering of Securities under the Registration Statement.

CONTRACTUAL RIGHTS OF RESCISSION

Original purchasers of Securities which are convertible, exchangeable or exercisable for other securities of the Company, including Subscription Receipts and Warrants if offered separately without any other Securities, will have a contractual right of rescission against the Company in respect of the conversion, exchange or exercise of such Securities. The contractual right of rescission will entitle such original purchasers to receive, in addition to the amount paid on original purchase of the Subscription Receipt or Warrant, as the case may be, the amount paid upon conversion, exchange or exercise, upon surrender of the underlying securities gained thereby, in the event that this Prospectus, the relevant Prospectus Supplement or an amendment thereto contains a misrepresentation, provided that: (i) the conversion, exchange or exercise takes place within 180 days of the date of the purchase of such Securities under this

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Prospectus and the applicable Prospectus Supplement; and (ii) the right of rescission is exercised within 180 days of the date of the purchase of such Securities under this Prospectus and the applicable Prospectus Supplement. This contractual right of rescission will be consistent with the statutory right of rescission described under section 131 of the Securities Act (British Columbia), and is in addition to any other right or remedy available to original purchasers under section 131 of the Securities Act (British Columbia) or otherwise at law.

GLOSSARY OF MINING TERMS

Canadian reporting requirements for disclosure of mineral properties are governed by NI 43-101. The definitions in NI 43-101 are adopted from those given by the Canadian Institute of Mining Metallurgy and Petroleum (“ CIM ”).

Mineral Resource

The term “mineral resource” refers to a concentration or occurrence of diamonds, natural, solid, inorganic or fossilized organic material including base and precious metals, coal and industrial minerals in or on the Earth’s crust in such form and quantity and of such a grade or quality that it has reasonable prospects for economic extraction. The location, quantity, grade, geological characteristics and continuity of a mineral resource are known, estimated or interpreted from specific geological evidence and knowledge.

Measured Mineral Resource

The term “measured mineral resource” refers to that part of a mineral resource for which quantity, grade or quality, densities, shape and physical characteristics are so well established that they can be estimated with confidence sufficient to allow the appropriate application of technical and economic parameters, to support production planning and evaluation of the economic viability of the deposit. The estimate is based on detailed and reliable exploration, sampling and testing information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes that are spaced closely enough to confirm both geological and grade continuity.

Indicated Mineral Resource

The term “indicated mineral resource” refers to that part of a mineral resource for which quantity, grade or quality, densities, shape and physical characteristics can be estimated with a level of confidence sufficient to allow the appropriate application of technical and economic parameters, to support mine planning and evaluation of the economic viability of the deposit. The estimate is based on detailed and reliable exploration and testing information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes that are spaced closely enough for geological and grade continuity to be reasonably assumed.

Inferred Mineral Resource

The term “inferred mineral resource” refers to that part of a mineral resource for which quantity and grade or quality can be estimated on the basis of geological evidence and limited sampling and reasonably assumed, but not verified, geological and grade continuity. The estimate is based on limited information and sampling gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes.

Qualified Person

The term “qualified person” refers to an individual who is an engineer or geoscientist with at least five years of experience in mineral exploration, mine development, production activities and project assessment, or any combination thereof, including experience relevant to the subject matter of the project or report and is a member in good standing of a self-regulating organization.

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STATUTORY RIGHTS OF WITHDRAWAL AND RESCISSION

Securities legislation in certain of the provinces of Canada provides purchasers with the right to withdraw from an agreement to purchase securities. This right may be exercised within two business days after receipt or deemed receipt of a prospectus and any amendment. In certain of the provinces of Canada, the securities legislation further provides a purchaser with remedies for rescission or, in some jurisdictions, revisions of the price or damages if the prospectus and any amendment contains a misrepresentation or is not delivered to the purchaser, provided that the remedies for rescission, revisions of the price or damages are exercised by the purchaser within the time limit prescribed by the securities legislation of the purchaser’s province. The purchaser should refer to any applicable provisions of the securities legislation of the purchaser’s province for the particulars of these rights or consult with a legal advisor.

In an offering of securities that are convertible, exchangeable or exercisable into other securities, purchasers are cautioned that the statutory right of action for damages for a misrepresentation contained in a prospectus is limited, in certain provincial securities legislation, to the price at which such securities are offered to the public under the prospectus offering. This means that, under the securities legislation of certain provinces, if the purchaser pays additional amounts upon conversion, exchange or exercise of such securities, those amounts may not be recoverable under the statutory right of action for damages that applies in those provinces. The purchaser should refer to any applicable provisions of the securities legislation of the purchaser’s province for the particulars of these rights, or consult with a legal advisor.

CERTIFICATE OF FIRST MINING GOLD CORP.

Dated: June 24, 2019

This short form base shelf prospectus, together with the documents incorporated in this prospectus by reference, will, as of the date of the last supplement to this prospectus relating to the securities offered by this prospectus and the supplement(s) constitute full, true and plain disclosure of all material facts relating to the securities offered by this prospectus and the supplement(s) as required by the securities legislation of each of the provinces of Canada.

FIRST MINING GOLD CORP.

(signed) “Daniel W. Wilton” (signed) “Andrew Marshall” By: Daniel W. Wilton By: Andrew Marshall Chief Executive Officer Chief Financial Officer

ON BEHALF OF THE BOARD OF DIRECTORS

(signed) “Keith Neumeyer” (signed) “David A. Shaw” By: Keith Neumeyer By: David A. Shaw Chairman Director

AI assistant

First Mining Gold Corp. — Capital/Financing Update 2020

45665_rns_2020-08-20_1f40f46a-ccb6-4ba8-bf1f-57b49985e2ae.pdf

PROSPECTUS SUPPLEMENT

FIRST MINING GOLD CORP.

Price: C$0.50 per Offered Unit

TABLE OF CONTENTS

PROSPECTUS SUPPLEMENT

BASE SHELF PROSPECTUS

IMPORTANT NOTICE ABOUT INFORMATION IN THIS PROSPECTUS

CAUTIONARY STATEMENTS REGARDING FORWARD-LOOKING INFORMATION

CAUTIONARY NOTE TO UNITED STATES INVESTORS REGARDING PRESENTATION OF MINERAL RESERVE AND MINERAL RESOURCE ESTIMATES

MEANING OF CERTAIN REFERENCES

CURRENCY AND EXCHANGE RATE INFORMATION

ELIGIBILITY FOR INVESTMENT

DOCUMENTS INCORPORATED BY REFERENCE

MARKETING MATERIALS

SUMMARY OF THE BUSINESS

Recent Developments

Treasury Metals

Notes:

Notes:

RISK FACTORS

Global Financial Conditions

Public Health Crises

Risks Relating to the Treasury Metals Transaction

No Assurance of Active or Liquid Market

Public Markets and Share Prices

Additional Issuances and Dilution

The Company has Broad Discretion in the Use of the Net Proceeds from the Offering and May Use Them in Ways Other than as Described Herein.

No Current Market for Warrants

Investors May Lose Their Entire Investment

CONSOLIDATED CAPITALIZATION

USE OF PROCEEDS

DESCRIPTION OF SECURITIES BEING DISTRIBUTED

Authorized Capital

Unit Shares and Warrant Shares

Warrants

PLAN OF DISTRIBUTION

Offering Jurisdictions

Settlement

Standstill

Lock Up

U.S. Securities Laws Matters

PRIOR SALES

Common Shares

Warrants

Stock Options

TRADING PRICE AND VOLUME

CERTAIN CANADIAN FEDERAL INCOME TAX CONSIDERATIONS

Allocation of Cost

Adjusted Cost Base of Unit Shares

Exercise of Warrants

Resident Holders

Expiry of Warrants

Dividends

Dispositions of Unit Shares, Warrant Shares and Warrants

Capital Gains and Capital Losses

Refundable Tax

Minimum Tax

Non-Resident Holders

Dividends

Dispositions of Unit Shares, Warrant Shares and Warrants

Non-Resident Holders whose Securities may constitute taxable Canadian property should consult their own tax advisors.

LEGAL MATTERS

AUDITOR, TRANSFER AGENT AND REGISTRAR

STATUTORY AND CONTRACTUAL RIGHTS OF WITHDRAWAL AND RESCISSION

INTERESTS OF EXPERTS

CERTIFICATE OF THE COMPANY

Dated: August 19, 2020

FIRST MINING GOLD CORP.

ON BEHALF OF THE BOARD OF DIRECTORS

CERTIFICATE OF THE UNDERWRITERS

Dated: August 19, 2020

CORMARK SECURITIES INC.

BMO NESBITT BURNS INC .

SHORT FORM BASE SHELF PROSPECTUS

FIRST MINING GOLD CORP.

$100,000,000

TABLE OF CONTENTS

First Mining Gold Corp. Capital/Financing Update 2020