<SEC-DOCUMENT>0001193125-18-214304-index.html : 20180709
<SEC-HEADER>0001193125-18-214304.hdr.sgml : 20180709
<ACCEPTANCE-DATETIME>20180709094002
ACCESSION NUMBER:		0001193125-18-214304
CONFORMED SUBMISSION TYPE:	424B3
PUBLIC DOCUMENT COUNT:		6
FILED AS OF DATE:		20180709
DATE AS OF CHANGE:		20180709

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:		424B3
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	333-225521
		FILM NUMBER:		18943539

	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>
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<TYPE>424B3
<SEQUENCE>1
<FILENAME>d600933d424b3.htm
<DESCRIPTION>424B3
<TEXT>
Document 1 - file: d600933d424b3.htm

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<SEQUENCE>2
<FILENAME>g600933g23n40.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 2 - file: g600933g23n40.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>3
<FILENAME>g600933g39k95.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 3 - file: g600933g39k95.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>4
<FILENAME>g600933g77z61.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 4 - file: g600933g77z61.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>5
<FILENAME>g600933g91d59.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 5 - file: g600933g91d59.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>6
<FILENAME>g600933g91i80.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 6 - file: g600933g91i80.jpg

</DOCUMENT>
</SEC-DOCUMENT>