Exhibit 31.1

CERTIFICATION OF CHIEF EXECUTIVE OFFICER

I, Richard J. Fitzpatrick, certify that:

1. I have reviewed this quarterly report on Form 10-Q of Cowlitz Bancorporation;

2. Based on my knowledge, this quarterly report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were
made, not misleading with respect to the period covered by this quarterly report;

3. Based on my knowledge, the financial statements, and other financial
information included in this quarterly report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this quarterly report;

4. The registrants other certifying officers and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act
Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) designed such disclosure controls and procedures to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities,
particularly during the period in which this quarterly report is being prepared;

b) designed such internal control over financial reporting, or caused
such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external reporting purposes in
accordance with generally accepted accounting principles;

c) evaluated the effectiveness of the registrants disclosure controls and procedures and
presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) disclosed in this quarterly report any change in the registrants internal control over financial reporting that occurred during the registrants most
recent fiscal quarter (the registrants first fiscal quarter in the case of this quarterly report) that has materially affected, or is likely to materially affect the registrants internal control over financial reporting;

5. The registrants other certifying officers and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the
registrants auditors and the audit committee of registrants board of directors (or persons performing the equivalent functions):

a) all
significant deficiencies in the design or operation of internal controls over financial reporting which are reasonably likely to adversely affect the registrants ability to record, process, summarize and report financial information; and

b) any fraud, whether or not material, that involves management or other employees who have a significant role in the registrants internal control
over financial reporting.

Date: May 15, 2009

/s/ Richard J. FitzpatrickRichard J. Fitzpatrick, Chief Executive Officer Cowlitz Bancorporation