First Interstate BancSystem, Inc. operates as a bank holding company for First Interstate Bank that provides a range of banking products and services in the United States. The company offers various traditional depository products, including checking, savings, and time deposits; and repurchase agreements primarily for commercial and municipal depositors. It also provides a range of trust, employee benefit, investment management, insurance, agency, and custodial services, including administration of estates and personal trusts; manages investment accounts for individuals; employee benefit plans and charitable foundations; and insurance planning. The company's loan portfolio includes real estate loans, such as commercial real estate, construction, residential, agricultural, and other real es…