Form of Common Stock Certificate



 Exhibit 4.3 
 

 
  
 NUMBER

 NYU 
 Columbia Banking System 
 Incorporated under the laws of the State of Washington 
 COMMON STOCK SHARES 
 CUSIP 197236 10 2 
 SEE REVERSE SIDE FOR DEFINITIONS AND A STATEMENT AS TO THE RIGHTS, PREFERENCES AND
PRIVILEGES OF, AND RESTRICTIONS ON, SHARES 
 THIS CERTIFIES THAT 
 is the owner of 
 Fully Paid and Non-Assessable Shares of Common Stock, With No Par Values, of 
 COLUMBIA BANKING SYSTEM, INC.

 CERTIFICATE OF STOCK 
 transferable on the books of the Corporation by the holder hereof in person or by duly authorized attorney upon surrender of this certificate properly endorsed. This certificate is not valid unless countersigned by the
Transfer Agent and registered by the Registrar. 
 WITNESS the facsimile signatures of its duly authorized officers.

 Dated: 
 President and Chief Executive Officer 
 Corporate Secretary 
 COUNTERSIGNED AND REGISTERED: 
 AMERICAN STOCK TRANSFER & TRUST COMPANY 
 TRANSFER AGENT AND REGISTRAR 
 BY 
 AUTHORIZED SIGNATURE 
 AMERICAN BANK NOTE COMPANY 
 711 ARMSTRONG LANE 
 COLUMBIA, TENNESSEE 38401 
 (931) 388-3003 
 7 / LIVE JOBS / C / COLUMBIA 25654 FC 
 PRODUCTION COORDINATOR: DENISE LITTLE 931-490-1706 
 PROOF OF: DECEMBER 22, 2006 
 COLUMBIA BANKING SYSTEM, INC. 
 TSB 25654 FC 
 OPERATOR: ANTHONY / RON 
 Rev. 1 
 COLORS SELECTED FOR PRINTING: LOGO IS PROCESS BLUE AND BLACK. Intaglio prints in SC-7 DARK BLUE. 
 COLOR:
This proof was printed from a digital file or artwork on a graphics quality, color laser printer. It is a good representation of the color as it will appear on the final product. However, it is not an exact color rendition, and the final printed
product may appear slightly different from the proof due to the difference between the dyes and printing ink. 
 PLEASE
INITIAL THE APPROPRIATE SELECTION FOR THIS PROOF: OK AS IS OK WITH CHANGES MAKE CHANGES AND SEND ANOTHER PROOF 







 

 
  
 COLUMBIA BANKING
SYSTEM, INC. 
 This certificate evidences shares of Common Stock of the Corporation. Other classes of shares of the
Corporation are, and may in the future be, authorized and outstanding, and those classes may consist of one or more series of shares, each with different rights, preferences and limitations. The Corporation will furnish to any shareholder upon
written request and without charge a full statement of the designations, preferences, limitations and relative rights of the shares of each class authorized to be issued and the variations in the relative rights and preferences between the shares of
each series of a class of shares so far as the same have been fixed and determined, and the authority of the Board of Directors to fix and determine the relative rights and preferences of the subsequent series. 
 The following abbreviations, when used in the inscription on the face of this certificate, shall be construed as though they were written
out in full according to applicable laws or regulations: 
 TEN COM — as tenants in common 
 TEN ENT — as tenants by the entireties 
 JT TEN — as joint tenants with right of survivorship and not as tenants in common 
 UNlF GIFT MIN ACT — Custodian 
 (Cust) (Minor) 
 under Uniform Gifts to Minors 
 Act 
 (State) 
 UNlF TRF MIN ACT — Custodian (until age) 
 (Cust) 
 under Uniform Transfers 
 (Minor) 
 to Minors Act 
 (State) 
 Additional abbreviations may also be used though not in the above
list. 
 FOR VALUE RECEIVED, hereby sell, assign and transfer unto 
 PLEASE INSERT SOCIAL SECURITY OR OTHER IDENTIFYING NUMBER OF ASSIGNEE 
 (PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS, INCLUDING ZIP CODE, OF ASSIGNEE) 
 Shares of the common stock represented by the within Certificate, and do hereby irrevocably constitute and appoint 
 Attorney to transfer the said stock on the books of the within named Corporation with full power of substitution in the premises.

 Dated: 
 NOTICE: THE SIGNATURE TO THIS ASSIGNMENT MUST CORRESPOND WITH THE NAME AS WRITTEN UPON THE FACE OF THE CERTIFICATE IN EVERY PARTICULAR, WITHOUT ALTERATION OR ENLARGEMENT OR ANY CHANGE WHATEVER. 
 Signature(s) Guaranteed 
 By 
 THE SIGNATURE(S) MUST BE GUARANTEED BY AN ELIGIBLE GUARANTOR INSTITUTION (BANKS, STOCKBROKERS, SAVINGS
AND LOAN ASSOCIATIONS AND CREDIT UNIONS WITH MEMBERSHIP IN AN APPROVED SIGNATURE GUARANTEE MEDALLION PROGRAM), PURSUANT TO S.E.C. RULE 17Ad-15 
 AMERICAN BANK NOTE COMPANY 
 711 ARMSTRONG LANE 
 COLUMBIA, TENNESSEE 38401 
 (931) 388-3003 
 7 / LIVE JOBS / C / COLUMBIA 25654 FC 
 PRODUCTION COORDINATOR: DENISE LITTLE 831-490-1706 
 PROOF OF: DECEMBER 13, 2006 
 COLUMBIA BANKING SYSTEM, INC. 
 TSB 25654 BK 
 OPERATOR: ANTHONY 
 NEW 
 PLEASE INITIAL THE APPROPRIATE SELECTION FOR THIS PROOF: OK AS IS OK WITH CHANGES MAKE CHANGES AND SEND ANOTHER PROOF