[Letterhead of Heller Ehrman White & McAuliffe]

                                                                   Exhibit 8.1


                               November 23, 1999

Cowlitz Bancorporation
927 Commerce Avenue
Longview, Washington 98632

     Ladies and Gentlemen:

     You have requested our opinion regarding certain federal income tax
consequences of the proposed merger (the "Merger") of Northern Bank of
Commerce ("Northern Bank") with and into Cowlitz Bank, a wholly-owned
subsidiary of Cowlitz Bankcorporation ("Cowlitz Bancorp").  Unless otherwise
defined, capitalized terms used herein have the meanings ascribed to them in
the Prospectus contained in Registration Statement No. 333-_____of Cowlitz
Bancorp on Form S-4 (the "Registration Statement") filed with the Securities
and Exchange Commission.  We have acted as counsel to Cowlitz Bancorp in
connection with the Merger and have examined and relied upon the Merger
Agreement dated September 14, 1999, among Cowlitz Bancorp, Cowlitz Bank and
Northern Bank (the "Agreement"), the exhibits and attachments thereto, the
Registration Statement, and such other instruments and documents related to
Cowlitz Bancorp, Cowlitz Bank, Northern Bank and the Merger as we have deemed
appropriate.

     Our opinion is based upon the understanding that the material facts are
as described in the Registration Statement, that the representations and
warranties in the Agreement are true, correct and complete, and that the
Merger will be effected in accordance with the terms set forth in the
Agreement.  In rendering our opinion we have relied upon such documents and
the foregoing representations without undertaking independently to verify the
accuracy and completeness of the matters covered thereby.

     Based upon the foregoing, it is our opinion that the statements in the
Registration Statement regarding the United States Federal income tax
consequences of the Merger, insofar as they constitute statements of United



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Cowlitz Bancorporation                                                 Page 2
November 23, 1999


States federal income tax law or legal conclusions, accurately summarize the
material United States federal income tax consequences of the Merger to a
Northern Bank shareholder.

                                *   *   *   *   *

     Our opinion is subject to certain assumptions and qualifications, and is
based on the truth and accuracy of the representations of the parties in the
Agreement.

     Our opinion is limited to the federal income tax consequences of the
Merger and does not address the tax consequences of transactions effected
prior to or after the Merger (whether or not in connection with the Merger),
or the effect of the Merger under the laws of the various state and local
governments or under the laws of any other jurisdiction.  Moreover, it does
not address special rules which may be applicable to particular shareholders
of Northern Bank, such as shareholders who acquired their shares pursuant to
the exercise of employee stock options, shareholders that are dealers or
foreign persons, or shareholders who exercise dissenter's rights.  We express
no opinion regarding any tax aspect or ramification of the Merger apart from
the opinion specifically set forth above.

     An opinion of counsel does not bind the Internal Revenue Service or
preclude it or a court from taking a position contrary to the opinion.  Our
opinion represents merely our best judgment as to the likely outcome of the
matters described above if litigated in an appropriate forum.  This opinion
is based upon the Code, the Treasury Regulations issued thereunder, and
judicial and administrative interpretations thereof, all as in effect on the
date of this opinion.  All of such authority is subject to change, including
retroactive change. We disclaim any obligation to advise of any developments
in areas covered by this opinion that occur after the date of this opinion.

     This opinion is rendered to you solely in connection with the filing of
the Registration Statement.  We hereby consent to the filing of this opinion
as an exhibit to the Registration Statement and to the references to our firm
in connection with the discussion of federal income taxes in the Registration
Statement.  In giving this consent, however, we do not admit that we are in
the category of persons whose consent is required under Section 7 of the
Securities Act of 1933, as amended.  This opinion may not be relied upon for
any other purpose without our written consent.

                                       Very truly yours,

                                       /s/ Heller Ehrman White & McAuliffe

                                       Heller Ehrman White & McAuliffe