Susan Scott Heyneman Trust, Susan Heyneman & First Interstate Wealth Management Co-Trustees

SEC source: 0001493152-25-025519 · ownership.xml · nonDerivative · entry 1

Susan Scott Heyneman Trust, Susan Heyneman & First Interstate Wealth Management Co-Trustees · CIK 0001908880 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 224,460

F1 · balance_after: Composed of 224,460 shares held of record by Susan Scott Heyneman Trust, Susan Heyneman & First Interstate Wealth Management Co-Trustees.

F2 · ownership.nature: As a result of certain agreements entered into by and among the reporting persons, the Issuer, and certain other stockholders of the Issuer, the reporting persons may be deemed members of a group with the other signatories thereto and may be deemed to share beneficial ownership of the securities reported herein. Each of the reporting persons disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein. The reporting persons expect to file future Forms 4, if any, together with Susan Scott Heyneman, Trust.

SEC source: 0001493152-25-020651 · ownership.xml · nonDerivative · entry 1

Susan Scott Heyneman Trust, Susan Heyneman & First Interstate Wealth Management Co-Trustees · CIK 0001908880 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 234,460

F1 · balance_after: Composed of 234,460 shares held of record by Susan Scott Heyneman Trust, Susan Heyneman & First Interstate Wealth Management Co-Trustees.

F2 · ownership.nature: As a result of certain agreements entered into by and among the reporting persons, the Issuer, and certain other stockholders of the Issuer, the reporting persons may be deemed members of a group with the other signatories thereto and may be deemed to share beneficial ownership of the securities reported herein. Each of the reporting persons disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein. The reporting persons expect to file future Forms 4, if any, together with Susan Scott Heyneman, Trust.

SEC source: 0001493152-25-016804 · ownership.xml · nonDerivative · entry 4

Susan Scott Heyneman Trust, Susan Heyneman & First Interstate Wealth Management Co-Trustees · CIK 0001908880 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 244,460

F1 · balance_after: Composed of 244,460 shares held of record by Susan Scott Heyneman Trust, Susan Heyneman & First Interstate Wealth Management Co-Trustees.

F2 · ownership.nature: As a result of certain agreements entered into by and among the reporting persons, the Issuer, and certain other stockholders of the Issuer, the reporting persons may be deemed members of a group with the other signatories thereto and may be deemed to share beneficial ownership of the securities reported herein. Each of the reporting persons disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein. The reporting persons expect to file future Forms 4, if any, together with Susan Scott Heyneman, Trust.

SEC source: 0001493152-25-016804 · ownership.xml · nonDerivative · entry 3

Susan Scott Heyneman Trust, Susan Heyneman & First Interstate Wealth Management Co-Trustees · CIK 0001908880 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 254,460

F2 · ownership.nature: As a result of certain agreements entered into by and among the reporting persons, the Issuer, and certain other stockholders of the Issuer, the reporting persons may be deemed members of a group with the other signatories thereto and may be deemed to share beneficial ownership of the securities reported herein. Each of the reporting persons disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein. The reporting persons expect to file future Forms 4, if any, together with Susan Scott Heyneman, Trust.

SEC source: 0001493152-25-016804 · ownership.xml · nonDerivative · entry 2

Susan Scott Heyneman Trust, Susan Heyneman & First Interstate Wealth Management Co-Trustees · CIK 0001908880 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 321,942

F2 · ownership.nature: As a result of certain agreements entered into by and among the reporting persons, the Issuer, and certain other stockholders of the Issuer, the reporting persons may be deemed members of a group with the other signatories thereto and may be deemed to share beneficial ownership of the securities reported herein. Each of the reporting persons disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein. The reporting persons expect to file future Forms 4, if any, together with Susan Scott Heyneman, Trust.

SEC source: 0001493152-25-016804 · ownership.xml · nonDerivative · entry 1

Susan Scott Heyneman Trust, Susan Heyneman & First Interstate Wealth Management Co-Trustees · CIK 0001908880 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 367,096

F2 · ownership.nature: As a result of certain agreements entered into by and among the reporting persons, the Issuer, and certain other stockholders of the Issuer, the reporting persons may be deemed members of a group with the other signatories thereto and may be deemed to share beneficial ownership of the securities reported herein. Each of the reporting persons disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein. The reporting persons expect to file future Forms 4, if any, together with Susan Scott Heyneman, Trust.

SEC source: 0001641172-25-026204 · ownership.xml · nonDerivative · entry 1

Susan Scott Heyneman Trust, Susan Heyneman & First Interstate Wealth Management Co-Trustees · CIK 0001908880 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 519,256

F1 · balance_after: Composed of 519,256 shares held of record by Susan Scott Heyneman Trust, Susan Heyneman & First Interstate Wealth Management Co-Trustees.

F2 · ownership.nature: As a result of certain agreements entered into by and among the reporting persons, the Issuer, and certain other stockholders of the Issuer, the reporting persons may be deemed members of a group with the other signatories thereto and may be deemed to share beneficial ownership of the securities reported herein. Each of the reporting persons disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein. The reporting persons expect to file future Forms 4, if any, together with Susan Scott Heyneman, Trust.

SEC source: 0001641172-25-021903 · ownership.xml · nonDerivative · entry 1

Susan Scott Heyneman Trust, Susan Heyneman & First Interstate Wealth Management Co-Trustees · CIK 0001908880 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 529,256

F3 · price: The price reported in column 4 is a weighted-average price. These shares were sold in multiple transactions at prices ranging form $27.60 to $28.28. The reporting person undertakes to provide to First Interstate BancSystem, Inc., any security holders of First Interstate BancSystem, Inc., or the staff of the Securities and Exchange Commission, upon request, the full information regarding the number of shares sold at each separate price within the ranges set forth above.

F1 · balance_after: Composed of 529,256 shares held of record by Susan Scott Heyneman Trust, Susan Heyneman & First Interstate Wealth Management Co-Trustees.

F2 · ownership.nature: As a result of certain agreements entered into by and among the reporting persons, the Issuer, and certain other stockholders of the Issuer, the reporting persons may be deemed members of a group with the other signatories thereto and may be deemed to share beneficial ownership of the securities reported herein. Each of the reporting persons disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein. The reporting persons expect to file future Forms 4, if any, together with Susan Scott Heyneman, Trust.

SEC source: 0001641172-25-019763 · ownership.xml · nonDerivative · entry 1

Susan Scott Heyneman Trust, Susan Heyneman & First Interstate Wealth Management Co-Trustees · CIK 0001908880 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 584,256

F3 · price: The price reported in column 4 is a weighted-average price. These shares were sold in multiple transactions at prices ranging form $30.85 to $31.31. The reporting person undertakes to provide to First Interstate BancSystem, Inc., any security holders of First Interstate BancSystem, Inc., or the staff of the Securities and Exchange Commission, upon request, the full information regarding the number of shares sold at each separate price within the ranges set forth above.

F1 · balance_after: Composed of 584,256 shares held of record by Susan Scott Heyneman Trust, Susan Heyneman & First Interstate Wealth Management Co-Trustees.

F2 · ownership.nature: As a result of certain agreements entered into by and among the reporting persons, the Issuer, and certain other stockholders of the Issuer, the reporting persons may be deemed members of a group with the other signatories thereto and may be deemed to share beneficial ownership of the securities reported herein. Each of the reporting persons disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein. The reporting persons expect to file future Forms 4, if any, together with Susan Scott Heyneman, Trust.

SEC source: 0001493152-22-019815 · ownership.xml · nonDerivative · entry 1

Heyneman Susan Scott · CIK 0001745809 · 10% owner

Susan Scott Heyneman Trust, Susan Heyneman & First Interstate Wealth Management Co-Trustees · CIK 0001908880 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 639,256

F1 · balance_after: Composed of 639,256 shares held of record by Susan Scott Heyneman Trust, Susan Heyneman & First Interstate Wealth Management Co-Trustees.

F2 · ownership.nature: As a result of certain agreements entered into by and among the reporting persons, the Issuer, and certain other stockholders of the Issuer, the reporting persons may be deemed members of a group with the other signatories thereto and may be deemed to share beneficial ownership of the securities reported herein. Each of the reporting persons disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein. The reporting persons expect to file future Forms 4, if any, together with Susan Scott Heyneman.

SEC source: 0000899243-22-012685 · doc4.xml · derivative · entry 2

Heyneman Susan Scott · CIK 0001745809 · 10% owner

Susan Scott Heyneman Trust, Susan Heyneman & First Interstate Wealth Management Co-Trustees · CIK 0001908880 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · see footnote

Disclosed balance after: 0

Underlying: Class A Common Stock · 646,756 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Pursuant to the Issuer's articles of incorporation, because the aggregate number of shares of Class B Common Stock constituted less than twenty percent (20%) of the aggregate number of shares of the Issuer's issued and outstanding common stock as of March 25, 2022, the record date of the Issuer's annual meeting of shareholders, each outstanding share of Class B Common Stock was automatically converted into one share of Class A Common Stock.

F1 · kind: Pursuant to the Issuer's articles of incorporation, because the aggregate number of shares of Class B Common Stock constituted less than twenty percent (20%) of the aggregate number of shares of the Issuer's issued and outstanding common stock as of March 25, 2022, the record date of the Issuer's annual meeting of shareholders, each outstanding share of Class B Common Stock was automatically converted into one share of Class A Common Stock.

F1 · derivative.exercise_date: Pursuant to the Issuer's articles of incorporation, because the aggregate number of shares of Class B Common Stock constituted less than twenty percent (20%) of the aggregate number of shares of the Issuer's issued and outstanding common stock as of March 25, 2022, the record date of the Issuer's annual meeting of shareholders, each outstanding share of Class B Common Stock was automatically converted into one share of Class A Common Stock.

F1 · derivative.expiration_date: Pursuant to the Issuer's articles of incorporation, because the aggregate number of shares of Class B Common Stock constituted less than twenty percent (20%) of the aggregate number of shares of the Issuer's issued and outstanding common stock as of March 25, 2022, the record date of the Issuer's annual meeting of shareholders, each outstanding share of Class B Common Stock was automatically converted into one share of Class A Common Stock.

F3 · ownership.nature: Composed of 646,756 shares held of record by Susan Scott Heyneman Trust, Susan Heyneman & First Interstate Wealth Management Co-Trustees.

SEC source: 0000899243-22-012685 · doc4.xml · nonDerivative · entry 1

Heyneman Susan Scott · CIK 0001745809 · 10% owner

Susan Scott Heyneman Trust, Susan Heyneman & First Interstate Wealth Management Co-Trustees · CIK 0001908880 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · see footnote

Disclosed balance after: 646,756

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · kind: Pursuant to the Issuer's articles of incorporation, because the aggregate number of shares of Class B Common Stock constituted less than twenty percent (20%) of the aggregate number of shares of the Issuer's issued and outstanding common stock as of March 25, 2022, the record date of the Issuer's annual meeting of shareholders, each outstanding share of Class B Common Stock was automatically converted into one share of Class A Common Stock.

F1 · price: Pursuant to the Issuer's articles of incorporation, because the aggregate number of shares of Class B Common Stock constituted less than twenty percent (20%) of the aggregate number of shares of the Issuer's issued and outstanding common stock as of March 25, 2022, the record date of the Issuer's annual meeting of shareholders, each outstanding share of Class B Common Stock was automatically converted into one share of Class A Common Stock.

F2 · balance_after: As a result of certain agreements entered into by and among the reporting persons, the Issuer, and certain other stockholders of the Issuer, the reporting persons may be deemed members of a group with the other signatories thereto and may be deemed to share beneficial ownership of the securities reported herein. Each of the reporting persons disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein. The reporting persons expect to file future Forms 4 and 5, if any, together with Susan Heyneman.

F3 · ownership.nature: Composed of 646,756 shares held of record by Susan Scott Heyneman Trust, Susan Heyneman & First Interstate Wealth Management Co-Trustees.