COLB · Annual Report (Form 10-K) · Filed February 26, 2026

Columbia Banking System Inc — 10-K exhibit

colb-20251231xex211x10k.htm

Columbia Banking System Inc on Boardroom Alpha

Document

Exhibit 21.1

Subsidiaries of Columbia Banking System, Inc.


Name of Subsidiary	State of Incorporation	Other Names Under Which Business is Conducted
Columbia Bank	Oregon	Columbia Trust Company, Columbia Healthcare Banking, Columbia Private Bank, Columbia Private Trust, Columbia Wealth Advisors, Columbia Wealth Management, Columbia Bank Home Lending, Columbia Bank Equipment Finance
Financial Pacific Reinsurance Co., Ltd.	Turks & Caicos Islands
Umpqua Master Trust I	Delaware
Umpqua Statutory Trust II	Delaware
Umpqua Statutory Trust III	Delaware
Umpqua Statutory Trust IV	Delaware
Umpqua Statutory Trust V	Connecticut
Humboldt Bancorp Statutory Trust II	Connecticut
Humboldt Bancorp Statutory Trust III	Connecticut
CIB Capital Trust	Delaware
Western Sierra Statutory Trust I	Connecticut
Western Sierra Statutory Trust II	Connecticut
Western Sierra Statutory Trust III	Delaware
Western Sierra Statutory Trust IV	Delaware
Klamath First Capital Trust I	Delaware
Lynnwood Financial Statutory Trust I	Connecticut
Lynnwood Financial Statutory Trust II	Delaware
Sterling Capital Trust III	Delaware
Sterling Capital Trust IV	Delaware
Sterling Capital Statutory Trust V	Connecticut
Sterling Capital Trust VI	Delaware
Sterling Capital Trust VII	Delaware
Sterling Capital Trust VIII	Delaware
Sterling Capital Trust IX	Delaware
Bank of Commerce Holdings Trust II	Delaware

Columbia Banking System, Inc. directly owns 100% of the voting stock or membership interest of each subsidiary listed above.

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