Exhibit 21.1
Subsidiaries of First Interstate BancSystem, Inc.
SubsidiaryState of Incorporation or Jurisdiction of OrganizationBusiness Name
First Interstate BankMontanaFirst Interstate Bank
FI Statutory Trust IConnecticutFI Statutory Trust I
FI Capital Trust IIDelawareFI Capital Trust II
FI Statutory Trust IIIDelawareFI Statutory Trust III
FI Capital Trust IVDelawareFI Capital Trust IV
FI Statutory Trust VDelawareFI Statutory Trust V
FI Statutory Trust VIDelawareFI Statutory Trust VI
Northwest Bancorporation Capital Trust IWashingtonNorthwest Bancorporation Capital Trust I