Exhibit 99.1

    CRAIG J. ORTEGA PROMOTED TO PRESIDENT OF COLUMBIA RIVER BANK

    THE DALLES, Ore., Aug. 22 /PRNewswire-FirstCall/ -- Columbia Bancorp
(Nasdaq: CBBO), the bank holding company for Columbia River Bank, today
announced the promotion of Craig J. Ortega to the position of President and
Chief Operating Officer of Columbia River Bank.

    Ortega most recently served as Columbia River Bank's Executive Vice
President and Chief Operating Officer (COO). As President and COO, he will have
responsibility for the day-to-day operations of the Bank and will report to
Roger Christensen, who continues as Chief Executive Officer of Columbia River
Bank and President and Chief Executive Officer of the holding company.

    "As the Bank has executed our growth strategies, it has naturally become
more complex," said Mr. Christensen. "Craig has interacted extensively with our
customers and investors and is a knowledgeable and credible spokesperson for our
company. This promotion will allow me to focus on strategy and long term goals
for Columbia Bancorp's continued success," concluded Christensen.

    Ortega has been in banking since 1978 and joined Columbia River Bank in 1993
as the manager of the Hood River Branch. He became an Executive Officer in 1997
and has held the title of Executive Vice President and Chief Operating Officer
of Columbia River Bank since September 2004.

    Ortega attended Blue Mountain Community College and holds a Bachelor of
Science degree in Business Administration from Eastern Oregon State College, and
is a graduate of the Pacific Coast Banking School. He presently serves as
President of the Independent Community Banks of Oregon and as a member of the
Oregon Bankers Association Board.

    About Columbia River Bank

    Columbia River Bank ( www.columbiariverbank.com ) operates 23 branches
located in The Dalles (2), Hood River, Bend (4), Madras, Redmond (2), Pendleton,
Hermiston, McMinnville (3), Canby and Newberg, Oregon; and in Goldendale, White
Salmon, Richland, Pasco, Yakima and Sunnyside, Washington. Columbia River Bank
also provides mortgage-lending services through CRB Mortgage Team and brokerage
services through CRB Financial Services Team.

SOURCE  Columbia Bancorp
    -0-                             08/22/2006
    /CONTACT:  Roger L. Christensen, President and CEO, +1-541-298-6633, or
rchristensen@columbiabancorp.com, or Greg B. Spear, Executive Vice President
and CFO, +1-541-298-6612, or gspear@columbiabancorp.com, both of Columbia
Bancorp/
    /Web site:  http://www.columbiariverbank.com
                http://www.columbiabancorp.com /