FIRST INTERSTATE BANCSYSTEM INC — Director's Dealing 2013

May 28, 2013

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: FIRST INTERSTATE BANCSYSTEM INC (FIBK)
CIK: 0000860413
Period of Report: 2013-05-24

Reporting Person: GUENTHNER KEVIN (SVP & Chief Infor. Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2013-05-24	Class A Common Stock	M	4383	$14.26	Acquired	18690	Direct
2013-05-24	Class A Common Stock	F	3470	$0.00	Disposed	15220	Direct
2013-05-24	Class A Common Stock	C	3158	$0.00	Acquired	18378	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2013-05-24	Stock Options	$17.00	M	12000	Disposed	2016-01-26	Class B Common Stock (12000)	Direct
2013-05-24	Stock Options	$15.25	M	4620	Disposed	2019-05-15	Class B Common Stock (4620)	Direct
2013-05-24	Stock Options	$15.00	M	4908	Disposed	2020-02-12	Class B Common Stock (4908)	Direct
2013-05-24	Stock Options	$14.20	M	2894	Disposed	2021-02-14	Class A Common stock (2894)	Direct
2013-05-24	Stock Options	$14.37	M	1489	Disposed	2022-02-17	Class A Common Stock (1489)	Direct
2013-05-24	Class B Common Stock	$0.00	M	21528	Acquired	2029-12-31	Class A Common Stock (21528)	Direct
2013-05-24	Class B Common Stock	$0.00	F	18370	Disposed	2029-12-31	Class A Common Stock (18370)	Direct
2013-05-24	Class B Common Stock	$0.00	C	3158	Disposed	2029-12-31	Class A Common Stock (3158)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Class A Common Stock	8760	Indirect

Footnotes

F1: The price reported in Column 4 of Table I is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $14.20 to $14.37. Reporting Person undertakes to provide to First Interstate BancSystem, Inc., any security holder of First Interstate BancSystem, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding number of shares purchased at each separate price within the range set forth in this Form 4.

F2: Includes 3,014 shares for payment of option exercise price and 456 shares for payment of taxes, valued at $20.73 per share.

F3: On March 5, 2010, the Company recapitalized its existing common stock. The recapitalization included, among other things, a redesignation of existing common stock as Class B common stock, a four-for-one split of Class B common stock, and the creation of a new class of common stock designated as Class A common stock, which is listed on the NASDAQ stock market under the symbol "FIBK". The Class B common stock is convertible at any time into Class A common stock on a share for share basis at the descretion of the holder. The conversion feature of the Class B common stock does not expire.

F4: The price reported in Column 8 of Table II is a weighted average price. These shares of Class B stock were purchased in multiple transactions at prices ranging from $15.00 to $17.00, and immediately converted to Class A common stock. Reporting Person undertakes to provide to First Interstate BancSystem, Inc., any security holder of First Interstate BancSystem, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding number of shares purchased at each separate price within the range set forth in this Form 4.

F5: Includes 16,791 shares for payment of option exercise price and 1,579 shares for payment of taxes, valued at $20.73 per share.