COLUMBIA BANKING SYSTEM INC

Regulation FD Disclosure

Other Events

Beneficial ownership report for a passive holder of more than 5% (Schedule 13G) (amendment)

General form for quarterly reports under Section 13 or 15(d)

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers: Compensatory Arrangements of Certain Officers

Results of Operations and Financial Condition

Regulation FD Disclosure

Annual reports of employee stock purchase savings and similar plans pursuant to Section 15(d)

Annual reports of employee stock purchase savings and similar plans pursuant to Section 15(d) (amendment)

Submission of Matters to a Vote of Security Holders

Other Events

General form for quarterly reports under Section 13 or 15(d)

Results of Operations and Financial Condition

Regulation FD Disclosure

Annual Report Scanned (Paper)

Annual reports of employee stock purchase savings and similar plans pursuant to Section 15(d)

Additional Information for Proxy Statement/ Votes

Definitive Proxy Statement

Annual report pursuant to Section 13 or 15(d)

Other Events

Results of Operations and Financial Condition

Regulation FD Disclosure

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers: Compensatory Arrangements of Certain Officers

Other Events

General form for quarterly reports under Section 13 or 15(d)

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers: Compensatory Arrangements of Certain Officers

Results of Operations and Financial Condition

Financial Statements and Exhibits

Completion of Acquisition or Disposition of Assets

Registration statement under Securities Act of 1933 to be offered to employees pursuant to certain plans

Regulation FD Disclosure

Other Events

General form for quarterly reports under Section 13 or 15(d)

Written communication about a business combination transaction (Rule 425)

Written communication about a business combination transaction (Rule 425)

Annual reports of employee stock purchase savings and similar plans pursuant to Section 15(d)

Prospectus Supplement for Primary Offering

Notice of Effectiveness

Correspondence with the SEC

Registration statement under Securities Act of 1933 (amendment)

Letter from the SEC

Registration statement under Securities Act of 1933

General form for quarterly reports under Section 13 or 15(d)

Written communication about a business combination transaction (Rule 425)

Written communication about a business combination transaction (Rule 425)

Written communication about a business combination transaction (Rule 425)

Written communication about a business combination transaction (Rule 425)

Written communication about a business combination transaction (Rule 425)

Written communication about a business combination transaction (Rule 425)

Written communication about a business combination transaction (Rule 425)

Written communication about a business combination transaction (Rule 425)

Written communication about a business combination transaction (Rule 425)

Written communication about a business combination transaction (Rule 425)

Written communication about a business combination transaction (Rule 425)

Written communication about a business combination transaction (Rule 425)

Written communication about a business combination transaction (Rule 425)

Annual Report Scanned (Paper)

Additional Information for Proxy Statement/ Votes

Definitive Proxy Statement

Annual reports of employee stock purchase savings and similar plans pursuant to Section 15(d)

Annual report pursuant to Section 13 or 15(d)

General form for quarterly reports under Section 13 or 15(d)

General form for quarterly reports under Section 13 or 15(d)

Annual reports of employee stock purchase savings and similar plans pursuant to Section 15(d)

General form for quarterly reports under Section 13 or 15(d)

Additional Information for Proxy Statement/ Votes

Annual Report Scanned (Paper)

Definitive Proxy Statement

Additional Information for Proxy Statement/ Votes

Annual report pursuant to Section 13 or 15(d)

General form for quarterly reports under Section 13 or 15(d)

General form for quarterly reports under Section 13 or 15(d)

Annual reports of employee stock purchase savings and similar plans pursuant to Section 15(d)

General form for quarterly reports under Section 13 or 15(d)

Annual Report Scanned (Paper)

Definitive Proxy Statement

Additional Information for Proxy Statement/ Votes

Annual report pursuant to Section 13 or 15(d)

General form for quarterly reports under Section 13 or 15(d)

General form for quarterly reports under Section 13 or 15(d)

General form for quarterly reports under Section 13 or 15(d)

Definitive Proxy Statement

Additional Information for Proxy Statement/ Votes

Annual report pursuant to Section 13 or 15(d)

Correspondence with the SEC

Letter from the SEC

General form for quarterly reports under Section 13 or 15(d)

Correspondence with the SEC

Letter from the SEC

Definitive Proxy Statement

Additional Information for Proxy Statement/ Votes

Definitive Proxy Statement

Additional Information for Proxy Statement/ Votes

Definitive Proxy Statement

Additional Information for Proxy Statement/ Votes

Definitive Proxy Statement

Correspondence with the SEC

Additional Information for Proxy Statement/ Votes

Definitive Proxy Statement

Correspondence with the SEC

Letter from the SEC

MACHUCA LUIS

GARDNER STEVEN R

LAGOMARSINO SIMONE

LAGOMARSINO SIMONE

Giem Judi

Deer Aaron James

MACHUCA LUIS

Moore Devine David

Moore Devine David

STUDENMUND JAYNIE M

Finkelstein Mark A

SEATON ELIZABETH WHITEHEAD

Forrest Eric

Lund Randal Lee

SCHULTZ JOHN F

Terry Hilliard C. III

Varnado Anddria

MACHUCA LUIS

MITCHELL M CHRISTIAN