<SEC-DOCUMENT>0000860413-18-000005-index.html : 20180130
<SEC-HEADER>0000860413-18-000005.hdr.sgml : 20180130
<ACCEPTANCE-DATETIME>20180130165320
ACCESSION NUMBER:		0000860413-18-000005
CONFORMED SUBMISSION TYPE:	8-K
PUBLIC DOCUMENT COUNT:		3
CONFORMED PERIOD OF REPORT:	20180130
ITEM INFORMATION:		Results of Operations and Financial Condition
ITEM INFORMATION:		Other Events
ITEM INFORMATION:		Financial Statements and Exhibits
FILED AS OF DATE:		20180130
DATE AS OF CHANGE:		20180130

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:		8-K
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34653
		FILM NUMBER:		18559738

	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>8-K
<SEQUENCE>1
<FILENAME>fibk20171231-8k.htm
<DESCRIPTION>8-K
<TEXT>
Document 1 - file: fibk20171231-8k.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.1
<SEQUENCE>2
<FILENAME>fibk-20171231x8kpr.htm
<DESCRIPTION>EXHIBIT 99.1
<TEXT>
Document 2 - file: fibk-20171231x8kpr.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>3
<FILENAME>fibbancsyst2line4ca03.jpg
<TEXT>
Document 3 - file: fibbancsyst2line4ca03.jpg

</DOCUMENT>
</SEC-DOCUMENT>