8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of

The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported):

4/26/07

COLUMBIA BANKING SYSTEM, INC.

(Exact name of registrant as specified in its charter)

Washington	0-20288	91-1422237
(State or other jurisdiction of incorporation)	(Commission File Number)	(IRS Employer Identification No.)

1301 A Street Tacoma, WA	98402
(Address of principal executive offices)	(Zip Code)

Registrant’s telephone number, including area code: (253) 305-1900

(Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

¨ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

¨ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 5.02(c) Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

On April 26, 2007, Columbia Banking System, Inc. (“Company”) announced that Kent L. Roberts, 56, Senior Vice President and Director of Human Resources was promoted to Executive Vice President.

Columbia Bank, the Company’s wholly owned subsidiary, had previously entered into a Change in Control Agreement with Mr. Roberts effective December 4, 2006. Under the terms of this agreement, in the event his employment is terminated in connection with a change in control (as defined in the agreement), he will receive severance benefits equal to one time his then-current annual base salary, vesting of all stock options and lapse of all restrictions with respect to restricted stock awards.

Mr. Roberts is not a party to any transaction with the Company that would require disclosure under Item 404(a) of Securities and Exchange Commission Regulation S-K. There are no arrangements or understandings between Mr. Roberts and any other person(s) pursuant to which he was selected as an executive officer. Mr. Roberts joined the Company in December 2006. Prior to that time, Mr. Roberts served as the Vice President, Organizational Development of Bird’s Eye Foods, the parent company of Nalley’s and Tim’s Cascade Potato Chips.

A copy of the press release announcing Mr. Roberts’ promotion is attached hereto as Exhibit 99.1, which is incorporated herein by reference.

Item 9.01 Financial Statements and Exhibits

(a) Financial statements. – not applicable

(b) Pro forma financial information. – not applicable

(c) Shell company transactions – not applicable

(d) The following exhibit is being furnished herewith:

99.1 Press Release of Columbia Banking System, Inc. dated April 26, 2007

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	COLUMBIA BANKING SYSTEM, INC.
Date: May 2, 2007	/s/ Melanie J. Dressel
	Melanie J. Dressel
	President and Chief Executive Officer

EX-99.1

Exhibit 99.1

FOR IMMEDIATE RELEASE

April 26, 2007

Contact: JoAnne Coy, Vice President

Corporate Communications

Columbia Bank

253-305-1965

Kent L. Roberts Named Executive Vice President by Columbia Bank

Tacoma, Washington – Columbia Bank announced that Kent L. Roberts, Senior Vice President and Director of Human Resources, has been promoted to Executive Vice President. Roberts joined Columbia Bank in January, 2007, upon the retirement of Executive Vice President and Human Resources Director, Tex Whitney.

“We are delighted to welcome Kent to our executive management team,” said Melanie Dressel, President and Chief Executive Officer of Columbia Banking System and Colombia Bank. “Kent joined the Columbia family in December last year, with over 30 years of human resource experience with Bird’s Eye Foods, the parent company of Nalley’s and Tim’s Cascade Potato Chips. His experience and dedication to fostering a dynamic culture for our employees is important to our mission of being a great place to work, as well as a great place to bank.”

Roberts earned a Bachelor’s degree in Communications from the University of Washington and is a former Board Chair for the United Way of Pierce County. He lives in University Place with his wife and daughter.

Columbia Bank is a Washington state-chartered, full-service commercial bank providing financial products and services to individuals, business and the real estate community. A wholly owned subsidiary of Columbia Banking System Inc, (NASDAQ: COLB) Columbia Bank currently operates 35 branches in Pierce, King, Cowlitz, Kitsap and Thurston counties. More information about Columbia can be found on its website at www.columbiabank.com.