8-K

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):

October 24, 2007

COLUMBIA BANKING SYSTEM, INC.

(Exact name of registrant as specified in its charter)

Washington

(State or other jurisdiction of incorporation)

0-20288	91-1422237
(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 obligations of the registrant under any of the following provisions:

¨ 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 of (17 CFR 240.14d-2(b))

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

Item 5.03 Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year

The rules adopted by Nasdaq and other exchanges mandate that by January 1, 2008, all issuers become “Direct Registration” eligible, which means that all listed companies, such as Columbia Banking System, Inc. (the “Company”) be eligible to have their shares issued via book entry, as opposed to physical certificates.

Accordingly, on October 24, 2007, the Company’s Board of Directors approved amending the Company’s Bylaws to allow the Company to issue its shares in book entry form. A copy of the Bylaw amendment, as adopted, is attached as Exhibit 3.1 to this report and is incorporated in its entirety by reference.

Item 9.01 Financial Statements and Exhibits

(a) Financial Statements: None

(b) Pro Forma Financial Information: None

(c) Shell Company Transactions. None

(d) Exhibits.

3.1 Article 5, Section 5.2 of the Company’s Bylaws, as amended.

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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: October 25, 2007	/s/ Melanie J. Dressel
	Melanie J. Dressel
	President and Chief Executive Officer

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EX-3.1

Exhibit 3.1

COLUMBIA BANKING SYSTEM, INC.

AMENDMENT TO BYLAWS

(For Adoption at the Board Meeting of October 24, 2007)

ARTICLE 5. Shares and Certificates for Shares

SECTION 5.2—Stock Certificates. Shares may but need not be represented by certificates. Certificates, if utilized, shall be signed by the Chief Executive Officer and the Secretary, or any other two officers as may be designated by the Board of Directors, and may be sealed with the seal of the corporation or a facsimile thereof. The signatures of such officers may be facsimiles. If an officer who has signed or whose facsimile signature has been placed upon such certificate ceases to be an officer before the certificate is issued, it may be issued by the corporation with the same effect as if the person were an officer on the date of issue. Each newly-issued certificate of stock at a minimum shall state:

(a) the name of the corporation and that it is organized under the laws of the State of Washington;

(b) the name of the person to whom issued; and

(c) the number and class of shares and the designation of the series, if any, which such certificate represents.