Sec Form 4 Filing - Homer Scott Jr Trust, Homer Scott Jr. & First Interstate Wealth Management Co Trustees @ FIRST INTERSTATE BANCSYSTEM INC - 2023-12-14

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Homer Scott Jr Trust, Homer Scott Jr. & First Interstate Wealth Management Co Trustees 2. Issuer Name and Ticker or Trading Symbol FIRST INTERSTATE BANCSYSTEM INC [ FIBK] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) PO BOX 2007 3. Date of Earliest Transaction (MM/DD/YY) 12/14/2023 (Street) SHERIDAN, WY82801 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 12/14/2023 S 1,000,000 D $ 32.14 950,753 ( 1 ) I See Footnote ( 1 ) ( 2 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Homer Scott Jr Trust, Homer Scott Jr. & First Interstate Wealth Management Co Trustees PO BOX 2007 SHERIDAN, WY82801 X Signatures HOMER SCOTT JR TRUST. HOMER SCOTT JR. & FIRST INTERSTATE WEAL TH MANAGEMENT CO TRUSTEES.By: /s/ Timothy Leuthold, Attorney-in-Fact for Reponing Person 12/15/2023 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Composed of 950,753 shares held of record by Homer Scott Jr Trust, First Interstate Wealth Management, Trustee, over which Sandra Scott Suzor has sole voting power and First Interstate Wealth Management has sole dispositive power over the same shares. ( 2 )As a result of certain agreements entered into by and among the reporting person, the Issuer, and certain other stockholders of the Issuer, the reporting person may be deemed a member of a group with the other signatories thereto. The reporting person disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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