EX-21.1 6 fibk-20241231xex211_subsid.htm EX-21.1

Exhibit 21.1

Subsidiaries of First Interstate BancSystem, Inc.

Subsidiary

State of Incorporation or Jurisdiction of Organization

Business Name

First Interstate Bank

Montana

First Interstate Bank

FI Statutory Trust I

Connecticut

FI Statutory Trust I

FI Capital Trust II

Delaware

FI Capital Trust II

FI Statutory Trust III

Delaware

FI Statutory Trust III

FI Capital Trust IV

Delaware

FI Capital Trust IV

FI Statutory Trust V

Delaware

FI Statutory Trust V

FI Statutory Trust VI

Delaware

FI Statutory Trust VI

Northwest Bancorporation Capital Trust I

Delaware

Northwest Bancorporation Capital Trust I

Great Western Statutory Trust IV

Connecticut

Great Western Statutory Trust IV

GWB Capital Trust VI

Delaware

GWB Capital Trust VI

HF Financial Capital Trust III

Delaware

HF Financial Capital Trust III

HF Financial Capital Trust IV

Delaware

HF Financial Capital Trust IV

HF Financial Capital Trust V

Delaware

HF Financial Capital Trust V

HF Financial Capital Trust VI

Delaware

HF Financial Capital Trust VI

Sunstate Bancshares Trust II

Delaware

Sunstate Bancshares Trust II