Group 1 - Columbia Banking System, Inc. will release its third quarter 2025 financial results on October 30, 2025, after market close [1] - A conference call for investors and analysts will be held at 2:00 p.m. PT (5:00 p.m. ET) on the same day, including a live question-and-answer session [1] - Participants can register for the call to receive dial-in details and unique PINs or join the listen-only audiocast [1] Group 2 - Columbia Banking System, Inc. is headquartered in Tacoma, Washington, and is the parent company of Columbia Bank, which was renamed from Umpqua Bank effective July 1, 2025 [4] - Columbia Bank is the largest bank headquartered in the Northwest and one of the largest in the West, with over $50 billion in assets and locations across several states [2] - The bank offers a full suite of services, including retail and commercial banking, SBA lending, institutional and corporate banking, and equipment leasing, along with investment and wealth management services [2]

Group 1 - Columbia Banking System, Inc. will participate in the Barclays 23rd Annual Global Financial Services Conference on September 10, 2025, at 11:15 a.m. ET [1] - A live audiocast of the presentation will be available on the company's investor relations website, which may include forward-looking statements [2] - Columbia Banking System, Inc. is headquartered in Tacoma, Washington, and is the parent company of Columbia Bank, which is the largest bank headquartered in the Northwest with over $50 billion in assets [3] Group 2 - Columbia Bank offers a full suite of services including retail and commercial banking, Small Business Administration lending, institutional and corporate banking, and equipment leasing [3] - Customers of Columbia Bank have access to investment and wealth management services through Columbia Wealth Advisors and Columbia Trust Company [3]

Group 1 - Columbia Banking System, Inc. will participate in the Barclays 23rd Annual Global Financial Services Conference on September 10, 2025, at 11:15 a.m. ET [1] - A live audiocast of the presentation will be available on the company's investor relations website [2] - Columbia Banking System is headquartered in Tacoma, Washington, and is the parent company of Columbia Bank, which is the largest bank headquartered in the Northwest with over $50 billion in assets [3] Group 2 - Columbia Bank offers a full suite of services including retail and commercial banking, Small Business Administration lending, institutional and corporate banking, and equipment leasing [3] - Customers of Columbia Bank have access to investment and wealth management services through Columbia Wealth Advisors and Columbia Trust Company [3]