<SEC-DOCUMENT>0000887343-20-000131-index.html : 20200417
<SEC-HEADER>0000887343-20-000131.hdr.sgml : 20200417
<ACCEPTANCE-DATETIME>20200417151150
ACCESSION NUMBER:		0000887343-20-000131
CONFORMED SUBMISSION TYPE:	DEFA14A
PUBLIC DOCUMENT COUNT:		5
FILED AS OF DATE:		20200417
DATE AS OF CHANGE:		20200417
EFFECTIVENESS DATE:		20200417

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			COLUMBIA BANKING SYSTEM, INC.
		CENTRAL INDEX KEY:			0000887343
		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
		IRS NUMBER:				911422237
		STATE OF INCORPORATION:			WA
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		DEFA14A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-20288
		FILM NUMBER:		20799232

	BUSINESS ADDRESS:	
		STREET 1:		1301 A STREET
		CITY:			TACOMA
		STATE:			WA
		ZIP:			98402
		BUSINESS PHONE:		2533051900

	MAIL ADDRESS:	
		STREET 1:		1301 A STREET
		CITY:			TACOMA
		STATE:			WA
		ZIP:			98402

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	COLUMBIA BANKING SYSTEM INC
		DATE OF NAME CHANGE:	19930328
</SEC-HEADER>
<DOCUMENT>
<TYPE>DEFA14A
<SEQUENCE>1
<FILENAME>defa14a2019proxy.htm
<DESCRIPTION>DEFA14A
<TEXT>
Document 1 - file: defa14a2019proxy.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>2
<FILENAME>proxyntcpage3a001.jpg
<TEXT>
Document 2 - file: proxyntcpage3a001.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>3
<FILENAME>proxyntcpage0a01.jpg
<TEXT>
Document 3 - file: proxyntcpage0a01.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>4
<FILENAME>proxyntcpage1a01.jpg
<TEXT>
Document 4 - file: proxyntcpage1a01.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>5
<FILENAME>proxyntcpage2a01.jpg
<TEXT>
Document 5 - file: proxyntcpage2a01.jpg

</DOCUMENT>
</SEC-DOCUMENT>