Columbia Banking System Announces $0.36 Per Common Share Dividend

TACOMA, Wash., November 15, 2024 – Columbia Banking System, Inc. (“Columbia” Nasdaq: COLB), parent company of Umpqua Bank, today announced its Board of Directors has approved a quarterly cash dividend in the amount of $0.36 per common share, payable December 16, 2024, to shareholders of record as of November 29, 2024.

About Columbia

Columbia (Nasdaq: COLB) is headquartered in Tacoma, Washington and is the parent company of Umpqua Bank, an award-winning western U.S. regional bank based in Lake Oswego, Oregon. Umpqua Bank is the largest bank headquartered in the Northwest and one of the largest banks headquartered in the West with locations in Arizona, California, Colorado, Idaho, Nevada, Oregon, Utah, and Washington. With over $50 billion of assets, Umpqua Bank combines the resources, sophistication and expertise of a national bank with a commitment to deliver superior, personalized service. The bank supports consumers and businesses through a full suite of services, including retail and commercial banking; Small Business Administration lending; institutional and corporate banking; and equipment leasing. Umpqua Bank customers also have access to comprehensive investment and wealth management expertise as well as healthcare and private banking through Columbia Wealth Advisors and Columbia Trust Company, a division of Umpqua Bank. Learn more at www.columbiabankingsystem.com.

Investor Relations Contact:

Jacquelynne “Jacque” Bohlen

ir@umpquabank.com

(503) 727-4100

Note Regarding Forward Looking Statements

This news release includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, which can be identified by words such as "may," "expected," "anticipate," "continue," or other comparable words. In addition, all statements other than statements of historical facts that address activities that Columbia expects or anticipates will or may occur in the future are forward-looking statements. Readers are encouraged to read the SEC reports of Columbia, particularly its Form 10-K for the Fiscal Year ended December 31, 2023, for meaningful cautionary language discussing why actual results may vary materially from those anticipated by management.

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