<SUBMISSION>
<ACCESSION-NUMBER>0001193125-07-068060
<TYPE>425
<PUBLIC-DOCUMENT-COUNT>2
<FILING-DATE>20070329
<DATE-OF-FILING-DATE-CHANGE>20070329
<SUBJECT-COMPANY>
<COMPANY-DATA>
<CONFORMED-NAME>COLUMBIA BANKING SYSTEM INC
<CIK>0000887343
<ASSIGNED-SIC>6022
<IRS-NUMBER>911422237
<STATE-OF-INCORPORATION>WA
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<FILING-VALUES>
<FORM-TYPE>425
<ACT>34
<FILE-NUMBER>000-20288
<FILM-NUMBER>07725708
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>1102 BROADWAY PLAZA
<CITY>TACOMA
<STATE>WA
<ZIP>98402
<PHONE>2533051900
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>1102 BROADWAY PLAZA
<CITY>TACOMA
<STATE>WA
<ZIP>98402
</MAIL-ADDRESS>
</SUBJECT-COMPANY>
<FILED-BY>
<COMPANY-DATA>
<CONFORMED-NAME>COLUMBIA BANKING SYSTEM INC
<CIK>0000887343
<ASSIGNED-SIC>6022
<IRS-NUMBER>911422237
<STATE-OF-INCORPORATION>WA
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<FILING-VALUES>
<FORM-TYPE>425
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>1102 BROADWAY PLAZA
<CITY>TACOMA
<STATE>WA
<ZIP>98402
<PHONE>2533051900
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>1102 BROADWAY PLAZA
<CITY>TACOMA
<STATE>WA
<ZIP>98402
</MAIL-ADDRESS>
</FILED-BY>
<DOCUMENT>
<TYPE>425
<SEQUENCE>1
<FILENAME>d8k.htm
<DESCRIPTION>FORM 8-K
<TEXT>
<HTML><HEAD>
<TITLE>Form 8-K</TITLE>
</HEAD>
 <BODY BGCOLOR="WHITE">

<HR SIZE="3" NOSHADE COLOR="#000000" ALIGN="left"> <P STYLE="margin-top:3px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="5"><B>SECURITIES AND EXCHANGE COMMISSION </B></FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="3"><B>Washington, D.C. 20549 </B></FONT></P> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P><HR WIDTH="17%" SIZE="1" NOSHADE
COLOR="#000000"> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="5"><B>FORM 8-K </B></FONT></P> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P><HR WIDTH="17%" SIZE="1" NOSHADE
COLOR="#000000"> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="3"><B>CURRENT REPORT </B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman"
SIZE="3"><B>Pursuant to Section&nbsp;13 or 15(d) of </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="3"><B>the Securities Exchange Act of 1934 </B></FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>Date of Report (Date of earliest event reported): </B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="2"><B>March&nbsp;28, 2007 </B></FONT></P> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P><HR WIDTH="17%" SIZE="1" NOSHADE COLOR="#000000"> <P STYLE="margin-top:12px;margin-bottom:0px"
ALIGN="center"><FONT FACE="Times New Roman" SIZE="6"><B>COLUMBIA BANKING SYSTEM, INC. </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(Exact name of registrant as specified in its
charter) </B></FONT></P> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P><HR WIDTH="17%" SIZE="1" NOSHADE COLOR="#000000"> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman"
SIZE="2"><B>Washington </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(State or other jurisdiction of incorporation) </B></FONT></P> <P
STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" ALIGN="center">

<TR>
<TD WIDTH="50%"></TD>
<TD VALIGN="bottom" WIDTH="2%"></TD>
<TD WIDTH="48%"></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>0-20288</B></FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>91-1422237</B></FONT></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(Commission File Number)</B></FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>IRS Employer Identification No.</B></FONT></TD></TR>
</TABLE> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>1301 A Street </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="2"><B>Tacoma, WA 98402 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(Address of principal executive offices) (zip code) </B></FONT></P> <P
STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>Registrant&#146;s telephone number, including area code: (253)&nbsp;305-1900 </B></FONT></P> <P
STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(Former Name or former address, if changed since last report.) </B></FONT></P> <P
STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P><HR WIDTH="17%" SIZE="1" NOSHADE COLOR="#000000"> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">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: </FONT></P> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><FONT FACE="WINGDINGS">&#120;</FONT></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) </FONT></TD></TR></TABLE> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>

<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"></FONT><FONT FACE="WINGDINGS" SIZE="2" COLOR="#000000">&#168;</FONT><FONT FACE="Times New Roman" SIZE="2"></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) </FONT></TD></TR></TABLE> <P
STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"></FONT><FONT FACE="WINGDINGS" SIZE="2" COLOR="#000000">&#168;</FONT><FONT FACE="Times New Roman" SIZE="2"></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act of (17 CFR 240.14d-2(b)) </FONT></TD></TR></TABLE> <P
STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"></FONT><FONT FACE="WINGDINGS" SIZE="2" COLOR="#000000">&#168;</FONT><FONT FACE="Times New Roman" SIZE="2"></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act of (17 CFR 240.13e-4(c)) </FONT></TD></TR></TABLE> <P
STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P><HR SIZE="3" NOSHADE COLOR="#000000" ALIGN="left">

<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">


<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><B>Item&nbsp;1.01.</B></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2"><B>Entry into a Material Definitive Agreement </B></FONT></TD></TR></TABLE> <P STYLE="margin-top:6px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">On March&nbsp;28, 2007,
Columbia Banking System, Inc., Tacoma, Washington (&#147;Columbia&#148;) entered into a Plan and Agreement of Merger (the &#147;Merger Agreement&#148;) with Town Center Bancorp (&#147;TWBC&#148;). Under the terms of the Merger Agreement, TWBC will
merge with and into Columbia, and TWBC&#146;s bank subsidiary, Town Center Bank will merge with and into Columbia&#146;s subsidiary, Columbia State Bank (the &#147;Transaction&#148;). </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT
FACE="Times New Roman" SIZE="2">Effective at the time of the merger, each outstanding common share of TWBC will be exchanged for a unit of cash and Columbia common stock, the amount of which will be based on the price of Columbia&#146;s stock.
Consummation of the merger is subject to several conditions, including receipt of applicable regulatory approvals and approval by the shareholders of TWBC. For information regarding the terms of the Transaction, reference is made to the press
release dated March&nbsp;28, 2007, which is attached as Exhibit 99.1 and incorporated herein by reference. </FONT></P> <P STYLE="font-size:18px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><B>Item&nbsp;9.01.</B></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2"><B>Financial Statements and Exhibits </B></FONT></TD></TR></TABLE> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">(a) Financial
statements. &#150; not applicable </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">(b) Pro forma financial information. &#150; not applicable </FONT></P> <P
STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">(c) Exhibits. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:8%"><FONT FACE="Times New Roman" SIZE="2">99.1 Press Release dated
March&nbsp;28, 2007 </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">2 </FONT></P>


<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">

 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">SIGNATURES </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT
FACE="Times New Roman" SIZE="2">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. </FONT></P> <P
STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0">

<TR>
<TD WIDTH="48%"></TD>
<TD VALIGN="bottom" WIDTH="1%"></TD>
<TD WIDTH="2%"></TD>
<TD VALIGN="bottom" WIDTH="1%"></TD>
<TD WIDTH="48%"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">Dated: March&nbsp;28, 2007</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" COLSPAN="3"><FONT FACE="Times New Roman" SIZE="2">COLUMBIA BANKING SYSTEM, INC.</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">By:</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"> <P STYLE="margin-bottom:1px;border-bottom:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">/s/ Melanie J. Dressel</FONT></P></TD></TR>
<TR>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">Melanie J. Dressel</FONT></TD></TR>
<TR>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">President and Chief Executive Officer</FONT></TD></TR>
</TABLE> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">3 </FONT></P>

</BODY></HTML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.1
<SEQUENCE>2
<FILENAME>dex991.htm
<DESCRIPTION>PRESS RELEASE
<TEXT>
<HTML><HEAD>
<TITLE>Press Release</TITLE>
</HEAD>
 <BODY BGCOLOR="WHITE">

 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2"><B>Exhibit 99.1 </B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="right"><FONT
FACE="Times New Roman" SIZE="2"><B><U>FOR IMMEDIATE RELEASE </U></B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2"><B>March 28, 2007 </B></FONT></P> <P
STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" ALIGN="center">

<TR>
<TD WIDTH="50%"></TD>
<TD VALIGN="bottom" WIDTH="1%"></TD>
<TD WIDTH="49%"></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2">Contacts:</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2"><B>Melanie J. Dressel,</B> President and Chief Executive Officer</FONT></TD></TR>
<TR>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2">Columbia Banking System, Inc.</FONT></TD></TR>
<TR>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2">(253) 305-1911</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2"><B>Gary&nbsp;R.&nbsp;Schminkey</B>,&nbsp;Executive&nbsp;Vice&nbsp;President&nbsp;and&nbsp;Chief&nbsp;Financial&nbsp;Officer</FONT></TD></TR>
<TR>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2">Columbia Banking System, Inc.</FONT></TD></TR>
<TR>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2">(253) 305-1966</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2"><B>Bruce Bryant</B>, President and Chief Executive Officer</FONT></TD></TR>
<TR>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2">Town Center Bancorp</FONT></TD></TR>
<TR>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2">(503) 772-1620</FONT></TD></TR>
</TABLE> <P STYLE="margin-top:24px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>COLUMBIA BANKING SYSTEM, INC. ANNOUNCES AGREEMENT TO ACQUIRE </B></FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>TOWN CENTER BANCORP OF PORTLAND, OREGON </B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">TACOMA,
Washington, and PORTLAND, Oregon &#150; Columbia Banking System, Inc. (NASDAQ &#147;COLB&#148;) today announced the signing of a definitive agreement to acquire Town Center Bancorp (OTCBB: &#147;TWBC&#148;) of Portland, Oregon in a cash-and-stock
transaction valued at approximately $45.1 million (including value to optionholders), or $20.75 per Town Center share, based upon today&#146;s closing stock price for Columbia. </FONT></P> <P
STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Columbia Banking System also announced today the signing of a definitive agreement for the merger of Mountain Bank Holding Company, the holding company
for Mt. Rainier National Bank. Upon completion of the two transactions, the combined total assets will approach $2.9 billion and 51 branches. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman"
SIZE="2">The boards of both companies unanimously approved the transaction, which is subject to approval by Town Center Bancorp&#146;s shareholders, as well as regulatory approvals and other customary conditions of closing. Upon closing of the
transaction, which is anticipated to take place in the third quarter 2007, Town Center Bank, the banking subsidiary of Town Center Bancorp, will be merged into Columbia State Bank, a subsidiary of Columbia Banking System. </FONT></P> <P
STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Terms of the agreement call for Columbia to pay a unit of $9.382 in cash and 0.3391 of Columbia Banking System shares for each share of Town Center
Bancorp common stock. The actual value of the consideration paid for each share of Town Center Bancorp stock will depend </FONT>
</P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">1 </FONT></P>


<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">

 <P STYLE="margin-top:0px;margin-bottom:0px">
<FONT FACE="Times New Roman" SIZE="2">on the stock price of Columbia at the time of closing. In the aggregate, Columbia will pay approximately $19.3 million in cash and issue 698,182 shares of
common stock based on Town Center&#146;s current shares outstanding of 2,058,928, or $20.8 million in cash and 751,722 shares of Columbia stock if all outstanding Town Center Bancorp stock options are exercised prior to closing. Based on the
March&nbsp;28, 2007 closing price of $33.53, the value of the stock consideration is approximately $23.4 million. The transaction is expected to be accretive to Columbia&#146;s earnings in the first full year. The portion of the consideration that
is paid in Columbia shares is expected to be recognized as a tax-free exchange to Town Center shareholders. The agreement calls for any unexercised Town Center options to be converted into options to purchase Columbia&#146;s stock. </FONT></P> <P
STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">The addition of Town Center will give Columbia a presence in the Portland Metropolitan area and strengthen its southwestern Washington footprint. Founded
in 1997, Town Center Bank offers banking services to individuals, professionals and small business clients throughout the Portland Metropolitan area. As of December&nbsp;31, 2006, Town Center Bancorp had consolidated total assets of approximately
$133.4 million, net loans of $106.6 million, total deposits of $103.2 million and stockholders&#146; equity of $12.9 million. In 2006, Town Center Bancorp earned $2.1 million in net income, or an 18.1% return on average equity and a 1.68% return on
average assets. From 2002 to 2006, Town Center Bancorp grew assets, loans and deposits at an approximately 30% compound annual growth rate while growing earnings by over 40%. </FONT></P> <P
STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Bruce Bryant, President and Chief Executive Officer of Town Center Bancorp commented, &#147;We are very pleased to be joining the Columbia team, which
brings tremendous resources to our organization. This combination is significantly positive for our shareholders, employees and customers. With a similar culture and approach to banking, this merger creates an opportunity for us to increase our
product and service offerings as well as expand lending capabilities, all to the benefit of our clients throughout the Portland Metropolitan area.&#148; </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT
FACE="Times New Roman" SIZE="2">Melanie Dressel, President and Chief Executive Officer of Columbia Banking System added, &#147;We are very excited about this combination with Town Center and our entry into the Portland Metropolitan area. Bruce and
his team at Town Center have built a solid franchise that we believe we can together leverage with our additional products, capital and increased lending limits. We feel the culture and core values of the Town Center team match up perfectly with
what we have developed at Columbia.&#148; </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">2 </FONT></P>


<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">

 <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Columbia was advised in the transaction by D.A. Davidson&nbsp;&amp; Co., as financial advisor, and
Graham&nbsp;&amp; Dunn PC, as legal counsel. Town Center was advised by McAdams Wright Ragen, as financial advisor, and Foster Pepper LLP, as legal counsel. </FONT></P> <P STYLE="margin-top:18px;margin-bottom:0px"><FONT FACE="Times New Roman"
SIZE="2"><B>Conference Call </B></FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Columbia will host a conference call to discuss the acquisition tomorrow, on Thursday, March&nbsp;29, 2007
at 1:30 p.m. PDT. Interested investors, analysts, media representatives and the public are invited to listen to this discussion by calling 1-866-404-2271; Conference ID code 4044023. An accompanying presentation will be available on Columbia Banking
System&#146;s website at <U>www.columbiabank.com.</U> To access, go to &#147;The Latest Info&#148; on the home page and click on &#147;Conference Call Presentation.&#148; </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT
FACE="Times New Roman" SIZE="2">A conference call replay will be available from approximately 3:00 p.m. PDT on March&nbsp;29 through midnight PDT on Thursday, April&nbsp;5, 2007. The conference call replay can be accessed by dialing 1-800-642-1687
and entering Conference ID code 4044023. </FONT></P> <P STYLE="margin-top:18px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2"><B>About Columbia Banking System, Inc. </B></FONT></P> <P
STYLE="margin-top:6px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Columbia Banking System, Inc. (Columbia) is a Tacoma-based bank holding company with $2.6 billion in assets whose wholly owned banking subsidiaries are
Columbia State Bank and Bank of Astoria. Columbia State Bank is a Washington state-chartered full-service commercial bank with 35 banking offices in Pierce, King, Cowlitz, Kitsap and Thurston counties. Bank of Astoria, a federally insured commercial
bank headquartered in Astoria, Oregon, operates four branches in Clatsop County: Astoria, Warrenton, Seaside and Cannon Beach; and one branch in Manzanita in Tillamook County. More information about Columbia can be found on its website at
<U>www.columbiabank.com</U>. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">3 </FONT></P>


<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">

 <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2"><B>About Town Center Bancorp </B></FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px; text-indent:4%"><FONT
FACE="Times New Roman" SIZE="2">Town Center Bank is the primary operating subsidiary of Town Center Bancorp, a community-owned financial services holding company. The Bank was established in 1997 and the holding company was formed in April 2002.
Town Center Bancorp operates with a local Board of Directors and the Bank is a member of the Federal Deposit Insurance Corporation. Headquartered at 82nd&nbsp;&amp; King Road in Portland, Town Center Bank primarily serves individuals, professionals
and small business clients throughout the Portland Metropolitan and North Clackamas County areas. The Bank operates five branch offices in the North Clackamas and Northeast Portland area and a mortgage loan office, Town Center Mortgage, in Northeast
Portland. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">#### </FONT></P> <P STYLE="margin-top:18px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2"><B>Note Regarding Forward
Looking Statements </B></FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">This news release includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995,
which can be identified by words such as &#147;may,&#148; &#147;expected,&#148; &#147;anticipate,&#148; &#147;continue,&#148; or other comparable words. In addition, all statements other than statements of historical facts that address activities
that Columbia expects or anticipates will or may occur in the future are forward-looking statements. Readers are encouraged to read the SEC reports of Columbia, particularly its form 10-K for the Fiscal Year ended December&nbsp;31, 2006, for
meaningful cautionary language discussing why actual results may vary materially from those anticipated by management. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">4 </FONT></P>

</BODY></HTML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
