TACOMA, Wash., Jan 24 /PRNewswire-FirstCall/ — The Board of Directors of Columbia Banking System, Inc. announced that a quarterly cash dividend of $0.17 per share will be paid on February 20, 2008 to shareholders of record as of the close of business on February 6, 2008.

Melanie Dressel, President and Chief Executive Officer noted, “We value the ongoing investment of our shareholders.”

About Columbia

Headquartered in Tacoma, Washington, Columbia Banking System, Inc. is a Tacoma-based bank holding company whose wholly owned banking subsidiaries are Columbia Bank and Bank of Astoria, which operate a combined total of 53 branches. Columbia Bank is a Washington state-chartered full-service commercial bank. With the July 23, 2007 completion of the acquisitions of Mountain Bank Holding Company and Town Center Bancorp, Columbia Bank has 48 banking offices in Pierce, King, Cowlitz, Kitsap and Thurston counties in Washington State, and Clackamas and Multnomah counties in Oregon. Included in Columbia Bank are former branches of Mt. Rainier National Bank, doing business as Mt. Rainier Bank, with 7 branches in King and Pierce counties. Bank of Astoria, a federally insured commercial bank headquartered in Astoria, Oregon, operates four branches in Clatsop County: Astoria, Warrenton, Seaside and Cannon Beach; and one branch in Manzanita in Tillamook County. More information about Columbia can be found on its website at http://www.columbiabank.com.