First Mining Gold Corp. — Capital/Financing Update 2025

Jul 17, 2025

July 16, 2025

VIA SEDAR+

TO: British Columbia Securities Commission, as principal regulator
Alberta Securities Commission
Financial and Consumer Affairs Authority of Saskatchewan
The Manitoba Securities Commission
Ontario Securities Commission
Autorite des Marches Financiers (Quebec)
Nova Scotia Securities Commission
Financial and Consumer Services Commission (New Brunswick)
Prince Edward Island Securities Office
Office of the Superintendent of Securities (Newfoundland and Labrador)

RE: First Mining Gold Corp. (the "Company") — Prospectus Supplement

Reference is made to the Company’s prospectus supplement dated July 16, 2025 to a short form base shelf prospectus dated January 23, 2024 and all documents incorporated by reference therein (the “Prospectus”).

The undersigned, an authorized signatory of Stantec Consulting Ltd. (the “Firm”) and a qualified person, as defined in National Instrument 43-101 - Standards of Disclosure for Mineral Projects, hereby consents to the use of the Firm’s name in the Prospectus, including the documents incorporated by reference therein, in connection with references to the Firm’s involvement in the preparation of a technical report entitled “NI 43-101 Technical Report: Preliminary Economic Assessment on the Duparquet Gold Project, Quebec, Canada” with an effective date of September 15, 2023 and a report date of October 20, 2023 (the “Technical Report”) and to references to the Technical Report, or portions thereof, in the Prospectus and to the inclusion of information derived from the Technical Report in the Prospectus.

The undersigned hereby confirms that the Firm has read the Prospectus and it has no reason to believe that there are any misrepresentations in the information contained in the Prospectus that are derived from those sections of the Technical Report that the Firm was responsible for preparing or that are within its knowledge as a result of the services performed by the Firm in connection with the Technical Report.

[Signature page follows.]

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Stantec Consulting Ltd.

Per: (signed) "Sheldon Smith"

Name: Sheldon Smith, MES, P. Geo

Title: Senior Hydrologist