Columbia Banking System Inc is a registered bank holding company whose wholly-owned banking subsidiary is Columbia State Bank. The company provides a full range of banking services to small and medium sized businesses, professionals, and individuals throughout Washington, Oregon, Idaho, and California. The company's subsidiary Columbia Trust Company is an Oregon trust company that provides agency, fiduciary, and other related trust services with offices in Washington, Oregon, and Idaho. The firm offers various products and services under Personal Banking, Business Banking, and Wealth Management divisions.