<SEC-DOCUMENT>0001140361-21-041599-index.html : 20220118
<SEC-HEADER>0001140361-21-041599.hdr.sgml : 20220118
<ACCEPTANCE-DATETIME>20211214172734
<PRIVATE-TO-PUBLIC>
ACCESSION NUMBER:		0001140361-21-041599
CONFORMED SUBMISSION TYPE:	CORRESP
PUBLIC DOCUMENT COUNT:		2
FILED AS OF DATE:		20211214

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			FIRST INTERSTATE BANCSYSTEM INC
		CENTRAL INDEX KEY:			0000860413
		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
		IRS NUMBER:				810331430
		STATE OF INCORPORATION:			MT
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		CORRESP

	BUSINESS ADDRESS:	
		STREET 1:		P O BOX 30918
		STREET 2:		401 NO 31ST STREET
		CITY:			BILLINGS
		STATE:			MT
		ZIP:			59116-0918
		BUSINESS PHONE:		4062555300

	MAIL ADDRESS:	
		STREET 1:		P O BOX 30918
		STREET 2:		401 NO 31ST STREET
		CITY:			BILLINGS
		STATE:			MT
		ZIP:			59116-0918

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	FIRST INTERSTATE BANCSYSTEM OF MONTANA INC
		DATE OF NAME CHANGE:	19930615
</SEC-HEADER>
<DOCUMENT>
<TYPE>CORRESP
<SEQUENCE>1
<FILENAME>filename1.htm
<TEXT>
Document 1 - file: filename1.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>2
<FILENAME>ny20001148x3_img01.jpg
<TEXT>
Document 2 - file: ny20001148x3_img01.jpg

</DOCUMENT>
</SEC-DOCUMENT>