FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person * DRESSEL MELANIE J   2. Issuer Name and Ticker or Trading Symbol COLUMBIA BANKING SYSTEM INC [COLB] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) President and CEO (Last) (First) (Middle) 3. Date of Earliest Transaction (Month/Day/Year) 06/30/2006 (Street)   4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 06/30/2006   P   458 A $ 26.397 4,483 (1) D   Common Stock 06/30/2005   P   181 A $ 22.158 3,881 (1) D   Common Stock 12/31/2004   I V 15 A $ 24.7 5,277 I 401(k) Common Stock               46,932 I Family Trust LLC Common Stock               2,408 I North Mason Fiber Common Stock               10 I Shares owned by son. Common Stock               10 I Shares owned by son.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

NQSO (Right to Buy)

$ 7.2

04/23/2000

04/23/2005

Common Stock

3,310

3,310

D

ISO (Right to Buy)

$ 11.77

01/20/2002

01/20/2007

Common Stock

8,488

11,798

D

NQSO (Right to Buy)

$ 11.77

01/20/2002

01/20/2007

Common Stock

5,519

17,317

D

NQSO (Right to Buy)

$ 10.82

12/03/2003

12/05/2008

Common Stock

12,128

29,445

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
DRESSEL MELANIE J	X		President and CEO

Signatures

/s/Cathleen Dent		07/03/2006
**Signature of Reporting Person		Date
/s/ Kristy W. House		01/04/2005
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	This was an ESPP purchase.

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