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                                                                   EXHIBIT 10.20

                              AMENDED AND RESTATED

              COLUMBIA BANKING SYSTEM, INC. AND COLUMBIA STATE BANK

                                 LIFE INSURANCE
                    ENDORSEMENT METHOD SPLIT DOLLAR AGREEMENT

Insurer:         Massachusetts Mutual Life Insurance Company

Policy Number:

Insurer:         New York Life Insurance Company

Policy Number:

Insurer:         Union Central Life Insurance Company

Policy Number:

Owner:           Columbia State Bank

Insured:         Executive

Effective Date:  August 1, 2001

This Agreement is by and between Columbia Bank System, Inc., Columbia State
Bank; it's wholly owned subsidiary (either or both, as applicable, referred to
interchangeably as the "Company"), and Executive, a senior executive of the
Company.

I.   DEFINITIONS

     The term "Policy" shall refer to the above-cited policies as well any
     policies obtained, by means of 1035 exchange, to replace the above-cited
     policies. Policy definitions shall govern.

II.  POLICY TITLE AND OWNERSHIP

     The respective rights and duties of the Company and the Insured in the
     Policy shall be as follows:

     Title and ownership shall reside in the Company for its use and for the use
     of the Insured all in accordance with this Agreement. The Company alone
     may, to the extent of its interest, exercise the right to borrow or
     withdraw the Policy cash values or to terminate the Policy. Where the
     Company and the Insured, mutually agree to exercise the right to increase
     coverage under the Policy, then, in such event, the rights, duties and
     benefits of the parties to such increased coverage shall continue to be
     subject to the terms of this Agreement.

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III. BENEFICIARY DESIGNATION

     The Insured shall have the right and power to designate beneficiaries to
     receive his/her share of death proceeds, as provided in this Agreement.
     Likewise, the Insured shall have the right and power to elect and change a
     payment option for such beneficiaries.

IV.  PREMIUM PAYMENTS

     The Company shall pay premiums and the Insured shall not be responsible for
     any portion thereof.

V.   TAXABLE BENEFIT

     Annually the Insured will receive a taxable benefit equal to the assumed
     cost of insurance as required by the Internal Revenue Service. The Company
     (or its administrator) will report to the Insured such imputed income on
     Form W-2 or its equivalent.

VI.  DIVISION OF DEATH PROCEEDS

     The Company shall be entitled to the death proceeds of the Policy except
     that, subject to Paragraph VII herein, beneficiaries designated by the
     Insured in accordance with Paragraph III, shall be entitled to a split
     dollar share of the death proceeds.

     1.   If, at the time of his or her death, the Insured is employed by the
          Company, the Insured employee's beneficiary (ies), shall be entitled
          to an amount, as follows:

          (a)  If the Insured employee has not yet attained the age of seventy
               (70), the lesser of $1.2 million, or one hundred percent (100%)
               of the Net At Risk Insurance portion of the proceeds; Net At Risk
               Insurance portion of the proceeds is the aggregate total proceeds
               less the cash value of the Policies designated herein;

          (b)  If the Insured employee is seventy (70) or older, but not yet age
               eighty (80), the lesser of $1.0 million, or one hundred percent
               (100%) of the Net At Risk Insurance portion of the proceeds;

          (c)  If the Insured employee dies after the attainment of age eighty
               (80), the lesser of $750,000, or one hundred percent (100%) of
               the Net At Risk Insurance portion of the proceeds.

     2.   If, at the time of his or her death, the Insured is no longer employed
          by the Company but, prior to death, was eligible to receive payments
          under that certain Executive Supplemental Compensation Agreement dated
          as of August 1, 2001, by and between the Company and the Insured (the
          SERP Agreement), the Insured's beneficiary (ies), shall be entitled to
          an amount, as follows. (For purposes of this Paragraph VI, the term

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          Applicable Percentage shall refer to the Applicable Percentage as
          defined in the SERP Agreement and in effect as of the Insured's last
          date of employment with the Company.)

          (a)  If the Insured has not yet attained the age of seventy (70), the
               Applicable Percentage times the lesser of $1.2 million, or one
               hundred percent (100%) of the Net At Risk Insurance portion of
               the proceeds;

          (b)  If the Insured is seventy (70) or older, but not yet age eighty
               (80), the Applicable Percentage times the lesser of $1.0 million,
               or one hundred percent (100%) of the Net At Risk Insurance
               portion of the proceeds;

          (c)  If the Insured dies after the attainment of age eighty (80), the
               Applicable Percentage times the lesser of $750,000, or one
               hundred percent (100%) of the Net At Risk Insurance portion of
               the proceeds.

     3.   If the Company no longer employs the Insured at the time of death and
          the Insured was not eligible to receive payments under the SERP
          Agreement prior to death, the beneficiaries' share of Policy proceeds
          shall be $25,000.

     4.   The Company and the Insured's beneficiaries shall share any interest
          due on death proceeds in the same pro rata ratio as applies to death
          proceeds, respectively.

     5.   In the event that the Policy is terminated other than as a result of a
          termination of this Agreement pursuant to paragraph X, then the Bank
          shall pay to the Insured's beneficiary (ies) an amount which will
          provide a total after-tax death benefit equal to the benefit that the
          Insured would have received under Section 1 or 2 of this Paragraph VI
          if the Policy had not been terminated; provided, however, no benefit
          will be payable under Section 2(c) of this Paragraph VI if at the time
          of death the Policy is no longer in place due to a change in federal
          income tax treatment of Policy proceeds or action by bank regulatory
          authorities.

VII. DIVISION OF CASH SURRENDER VALUE

     The Company shall at all times be entitled to an amount equal to the
     Policy's cash value, as that term is defined in the Policy, less any Policy
     loans and unpaid interest or cash withdrawals previously incurred by the
     Company and any applicable Policy surrender charges. Such cash value shall
     be determined as of the date of surrender of the Policy or death of the
     Insured as the case may be.

VIII. PREMIUM WAIVER

     If the Policy contains a premium waiver provision, any such waived amounts
     shall be considered for all purposes of this Agreement as having been paid
     by the Company.

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IX.  RIGHTS OF PARTIES WHERE POLICY ENDOWMENT OR ANNUITY ELECTION EXISTS

     In the event the Policy involves an endowment or annuity element, the
     Company's right and interest in any endowment proceeds or annuity benefits
     shall be determined according to this Agreement, by regarding such
     endowment proceeds, or the commuted value of such annuity benefits, as the
     Policy's cash value. Such endowment proceeds or annuity benefits shall be
     treated like death proceeds for the purposes of division under this
     Agreement.

X.   TERMINATION OF AGREEMENT

     This Agreement shall terminate immediately upon the commission of any act
     by the Insured that results in the termination of the Policy by the
     Insurer.

     Except as provided above, this Agreement shall terminate upon distribution
     of death benefits in accordance with Paragraph VI above.

XI.  PROHIBITION ON ASSIGNMENT

     The Insured may not, without the prior written consent of the Company,
     assign to any individual, trust or other organization, any right, title or
     interest in the Policy or in any rights, options, privileges or duties
     created under this Agreement.

XII. AGREEMENT BINDING UPON THE PARTIES

     This Agreement shall be binding upon the Insured and the Company, and their
     respective heirs, successors, personal representatives and assigns, as
     applicable.

XIII. NAMED FIDUCIARY AND PLAN ADMINISTRATOR

     The Company is hereby designated the "Named Fiduciary" until resignation or
     removal by its Board of Directors. As Named Fiduciary, the Company shall be
     responsible for the management, control, and administration of this
     Agreement as established herein. The Named Fiduciary may allocate to others
     certain aspects of the management and operations responsibilities of this
     Agreement, including the employment of advisors and the delegation of any
     ministerial duties to qualified individuals.

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XIV. FUNDING POLICY

     The funding Policy for this Agreement shall be to maintain the Policy in
     force by paying, when due, all premiums required.

XV.  CLAIM PROCEDURES

     Claims shall be directed to The Benefit Marketing Group, Inc., Atlanta
     Georgia (770-952-1529). If a claim is payable, a benefit check will be
     issued to the Named Fiduciary. In the event that a claim is not eligible
     under the Policy, the Insurer will notify the Named Fiduciary of the denial
     as required by the Policy. If the Named Fiduciary is dissatisfied with the
     denial of the claim and wishes to contest such claim denial, it should
     contact the office named above and they will assist in making inquiry to
     the Insurer. All objections to the Insurer's actions should be in writing
     and submitted to the office named above for transmittal to the Insurer.

XVI. GENDER AND PLURAL VS SINGULAR

     Whenever in this Agreement words are used in the masculine or neuter
     gender, they shall be read and construed as in the masculine, feminine or
     neuter gender, whenever they should so apply. When applicable, nouns in the
     singular shall be read and construed as in the plural and visa versa.

XVII. INSURANCE COMPANY NOT A PARTY TO THIS AGREEMENT

     The Insurer shall not be deemed a party to this Agreement, but will be
     served with an executed copy of this Agreement. Payment or other
     performance in accordance with the Policy provisions shall fully discharge
     the Insurer from any and all liability.

IN WITNESS WHEREOF, the Insured and duly authorized Company officer have signed
this Agreement as of the above written date.

Columbia Banking System, Inc.                    Columbia State Bank

------------------------------                   ------------------------------
Name:   J. James Gallagher                       Name:   Melanie J. Dressel
Title:  Vice Chairman & Chief                    Title:  President and Chief
        Executive Officer                                Executive Officer

Executive

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Name:   Executive

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Executive Name:

                         BENEFICIARIES DESIGNATION FORM

Primary Designation:

            Name                                   Relationship

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Contingent Designation:

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________________________, 2002

Signed:
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         Executive

                                       6<PAGE>
                                                                   EXHIBIT 10.11

        AMENDMENT TO THE AMENDED AND RESTATED CHANGE IN CONTROL AGREEMENT

                   This Amendment (the "Amendment") to the Amended and Restated
Change in Control Agreement dated October 26, 2000 (the "Agreement") between
OSCA, Inc., a Delaware corporation (the "Company"), together with any of its
subsidiaries or successors in interest, including a successor in a Change in
Control (as defined in the Agreement), (the "Employer"), and __________________
(the "Executive") is made as of _____________, 2001.

                   WHEREAS, the parties desire to amend the Agreement changing
the definition of "Annual Compensation" and adding a provision requiring to
Employer to pay certain legal fees incurred by the Executive pertaining to this
Agreement.

                   NOW THEREFORE, for and in good and valuable consideration,
the receipt of which is hereby acknowledged, the changes to the Change in
Control Agreement are in effect effective August 29, 2001 as follows:

         1. The current Agreement defines Annual Compensation as follows:
Section 3. Certain Definitions, (a) "Annual Compensation" currently states: (a)
"Annual Compensation" means Executive's annual base salary as in effect
immediately prior to the Change in Control, plus an amount equal to all other
amounts paid to Executive as wages, bonuses, commissions, profit sharing or
other cash compensation for services rendered during the twelve month period
immediately prior to the Change in Control.

                  By this Amendment Section 3. Certain Definitions, (a) "Annual
Compensation" is replaced by the following provision:

                  (a) "Annual Compensation" means Executive's annual base
salary, plus bonus, deferred bonus, 401(K) contributions matched by the Company,
profit sharing contributions, make whole payments regarding 401(K) and profit
sharing contributions, plus payments made under the executive car program and an
amount equal to all other amounts paid to Executive as wages, and other cash
compensation for services rendered on an annualized basis. For purposes of
calculating an Executive's Annual Compensation, the calculation shall include
the highest amount for each category stated above paid by the Company to the
Executive for the last three years.

         2. In addition, a new paragraph, Section 11 Legal Fees, is added as
follows:

                  "11. Legal Fees. If after a Change in Control, the Executive
institutes any legal action in seeking to obtain or enforce or is required to
defend in any legal action the validity or enforceability of any right or
benefit provided by this Agreement, the Company shall pay for all actual legal
fees and expenses reasonably incurred (as incurred) by such Executive,
regardless of the outcome of such action."

         In WITNESS WHEREOF, the parties hereto have executed this Amendment to
the Agreement effective as of the date first written above. All other terms and
conditions of your Agreement remain unchanged.

         OSCA, Inc.

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         Executive:

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         Agreed and accepted

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