EX-32 6 fibk-20111231xex32.htm FIBK-2011.12.31-EX32


Exhibit 32
CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED
PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002
The undersigned are the Chief Executive Officer and the Chief Financial Officer of First Interstate BancSystem, Inc. (the “Registrant”). This Certification is made pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. This Certification accompanies the Annual Report on Form 10-K of the Registrant for the year ended December 31, 2011.
We certify to the best of our knowledge that such Annual Report on Form 10-K fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934 and that the information contained in the Form 10-K fairly presents, in all material respects, the financial condition and results of operations of the Registrant for the periods presented therein.

This Certification is executed as of February 27, 2012.
/s/ LYLE R. KNIGHT  
 
Lyle R. Knight 
 
President and Chief Executive Officer 
 
 
 
 
 
/s/ TERRILL R. MOORE  
 
Terrill R. Moore 
 
Executive Vice President and
Chief Financial Officer 
 
The forgoing certification is being furnished solely pursuant to Subsections (a) and (b) of Section 1350, Chapter 63 of Title 18, United States Code in accordance with Section 906 of the Sarbanes-Oxley Act of 2002 and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, or otherwise subject to the liability of that section, and shall not be deemed to be incorporated by reference into any filing under the Securities Act of 1933 or the Securities Exchange Act of 1934.