-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 GA/Ga49NRWdczyWpv72MxT4z3XHGYsSxqRB+SAlclMa4m0cznt+k1Rx8GbRCE2sF
 uwUe7i3NxYqxwCqF1YkR9g==

<SEC-DOCUMENT>0001209191-03-023416.txt : 20030930
<SEC-HEADER>0001209191-03-023416.hdr.sgml : 20030930
<ACCEPTANCE-DATETIME>20030930151225
ACCESSION NUMBER:		0001209191-03-023416
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030930
FILED AS OF DATE:		20030930

ISSUER:		

	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

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

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	FIRST INTERSTATE BANCSYSTEM OF MONTANA INC
		DATE OF NAME CHANGE:	19930615

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SULLIVAN MICHAEL J/CO
		CENTRAL INDEX KEY:			0001196795

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-49733
		FILM NUMBER:		03917430

	BUSINESS ADDRESS:	
		STREET 1:		C/O CIIRMAREX ENERGY CO
		STREET 2:		707 17TH ST. #3300
		CITY:			DENVER
		STATE:			CO
		ZIP:			80202-3404
		BUSINESS PHONE:		3032353995

	MAIL ADDRESS:	
		STREET 1:		C/O CIIRMAREX ENERGY CO
		STREET 2:		707 17TH ST. #3300
		CITY:			DENVER
		STATE:			CO
		ZIP:			80202-3404
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>bmn79717_bmn5mjs.xml
<DESCRIPTION>MAIN DOCUMENT DESCRIPTION
<TEXT>
<XML>
<?xml version="1.0"?><ownershipDocument><schemaVersion>X0201</schemaVersion>    <documentType>4</documentType><periodOfReport>2003-09-30</periodOfReport><notSubjectToSection16>0</notSubjectToSection16><issuer><issuerCik>0000860413</issuerCik><issuerName>FIRST INTERSTATE BANCSYSTEM INC</issuerName>        <issuerTradingSymbol>N/A</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId><rptOwnerCik>0001196795</rptOwnerCik><rptOwnerName>SULLIVAN MICHAEL J/CO</rptOwnerName></reportingOwnerId><reportingOwnerAddress><rptOwnerStreet1>123 WEST 1ST ST., SUITE 200</rptOwnerStreet1><rptOwnerStreet2></rptOwnerStreet2><rptOwnerCity>CASPER</rptOwnerCity><rptOwnerState>WY</rptOwnerState><rptOwnerZipCode>82501</rptOwnerZipCode><rptOwnerStateDescription></rptOwnerStateDescription></reportingOwnerAddress><reportingOwnerRelationship><isDirector>1</isDirector><isOfficer>0</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativ
eTransaction><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2003-09-30</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>P</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>1064</value></transactionShares><transactionPricePerShare><value>47</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>1064</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></nonDerivativeTransaction></nonDerivativeTable><ownerSignature><signatureName>/s/ Terrill R. Moore, Attorney in Fact for Reprting Person</signatureName><signatureDate>2003-09-30</signatureDate></ownerSignature></ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----