<SEC-DOCUMENT>0001047469-20-001534-index.html : 20200316
<SEC-HEADER>0001047469-20-001534.hdr.sgml : 20200316
<ACCEPTANCE-DATETIME>20200316173051
ACCESSION NUMBER:		0001047469-20-001534
CONFORMED SUBMISSION TYPE:	S-3ASR
PUBLIC DOCUMENT COUNT:		8
FILED AS OF DATE:		20200316
DATE AS OF CHANGE:		20200316
EFFECTIVENESS DATE:		20200316

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:		S-3ASR
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	333-237226
		FILM NUMBER:		20718390

	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>S-3ASR
<SEQUENCE>1
<FILENAME>a2241029zs-3asr.htm
<DESCRIPTION>S-3ASR
<TEXT>
Document 1 - file: a2241029zs-3asr.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-4.3
<SEQUENCE>2
<FILENAME>a2241029zex-4_3.htm
<DESCRIPTION>EX-4.3
<TEXT>
Document 2 - file: a2241029zex-4_3.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-4.4
<SEQUENCE>3
<FILENAME>a2241029zex-4_4.htm
<DESCRIPTION>EX-4.4
<TEXT>
Document 3 - file: a2241029zex-4_4.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-5.1
<SEQUENCE>4
<FILENAME>a2241029zex-5_1.htm
<DESCRIPTION>EX-5.1
<TEXT>
Document 4 - file: a2241029zex-5_1.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-5.2
<SEQUENCE>5
<FILENAME>a2241029zex-5_2.htm
<DESCRIPTION>EX-5.2
<TEXT>
Document 5 - file: a2241029zex-5_2.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-23.1
<SEQUENCE>6
<FILENAME>a2241029zex-23_1.htm
<DESCRIPTION>EX-23.1
<TEXT>
Document 6 - file: a2241029zex-23_1.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>7
<FILENAME>g123773kui001.jpg
<DESCRIPTION>G123773KUI001.JPG
<TEXT>
Document 7 - file: g123773kui001.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>8
<FILENAME>g131884.jpg
<DESCRIPTION>G131884.JPG
<TEXT>
Document 8 - file: g131884.jpg

</DOCUMENT>
</SEC-DOCUMENT>