    <SEC-DOCUMENT>0002090710-25-000004-index.html : 20251009
    <SEC-HEADER>0002090710-25-000004.hdr.sgml : 20251009
    <ACCEPTANCE-DATETIME>20251009174941
    ACCESSION NUMBER:		0002090710-25-000004
    CONFORMED SUBMISSION TYPE:	3
    PUBLIC DOCUMENT COUNT:		5
    CONFORMED PERIOD OF REPORT:	20250910
    FILED AS OF DATE:		20251009
    DATE AS OF CHANGE:		20251009

    REPORTING-OWNER:

    	OWNER DATA:
    		COMPANY CONFORMED NAME:			Shepler Christopher L.
    		CENTRAL INDEX KEY:			0002090710
    		ORGANIZATION NAME:

    	FILING VALUES:
    		FORM TYPE:		3
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	001-34653
    		FILM NUMBER:		251385982

    	MAIL ADDRESS:
    		STREET 1:		401 N. 31ST ST.
    		CITY:			BILLINGS
    		STATE:			MT
    		ZIP:			59101

    ISSUER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			FIRST INTERSTATE BANCSYSTEM INC
    		CENTRAL INDEX KEY:			0000860413
    		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
    		ORGANIZATION NAME:           	02 Finance
    		EIN:				810331430
    		STATE OF INCORPORATION:			DE
    		FISCAL YEAR END:			1231

    	BUSINESS ADDRESS:
    		STREET 1:		401 NO 31ST STREET
    		CITY:			BILLINGS
    		STATE:			MT
    		ZIP:			59101
    		BUSINESS PHONE:		4062555311

    	MAIL ADDRESS:
    		STREET 1:		401 NO 31ST STREET
    		CITY:			BILLINGS
    		STATE:			MT
    		ZIP:			59101

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	FIRST INTERSTATE BANCSYSTEM OF MONTANA INC
    		DATE OF NAME CHANGE:	19930615
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>3
    <SEQUENCE>1
    <FILENAME>wk-form3_1760046577.xml
    <DESCRIPTION>FORM 3
    <TEXT>
    Document 1 - file: wk-form3_1760046577.html

    Document 1 - RAW XML: wk-form3_1760046577.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-24
    <SEQUENCE>2
    <FILENAME>lpoa_chrisshepler.htm
    <DESCRIPTION>EX-24
    <TEXT>
    Document 2 - file: lpoa_chrisshepler.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>3
    <FILENAME>lpoa_chrisshepler001.jpg
    <DESCRIPTION>EX-24
    <TEXT>
    Document 3 - file: lpoa_chrisshepler001.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>4
    <FILENAME>lpoa_chrisshepler002.jpg
    <DESCRIPTION>EX-24
    <TEXT>
    Document 4 - file: lpoa_chrisshepler002.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>5
    <FILENAME>lpoa_chrisshepler003.jpg
    <DESCRIPTION>EX-24
    <TEXT>
    Document 5 - file: lpoa_chrisshepler003.jpg

    </DOCUMENT>
    </SEC-DOCUMENT>