<SUBMISSION>
<ACCESSION-NUMBER>0001181431-09-055596
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20091204
<FILING-DATE>20091208
<DATE-OF-FILING-DATE-CHANGE>20091208
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>POTLATCH CORP
<CIK>0001338749
<ASSIGNED-SIC>6798
<IRS-NUMBER>820156045
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>601 WEST FIRST AVENUE
<STREET2>SUITE 1600
<CITY>SPOKANE
<STATE>WA
<ZIP>99201
<PHONE>(509) 835-1500
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>601 WEST FIRST AVENUE
<STREET2>SUITE 1600
<CITY>SPOKANE
<STATE>WA
<ZIP>99201
</MAIL-ADDRESS>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>Potlatch Holdings, Inc.
<DATE-CHANGED>20050914
</FORMER-COMPANY>
</ISSUER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>PEIROS LARRY
<CIK>0001184042
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-32729
<FILM-NUMBER>091229127
</FILING-VALUES>
<MAIL-ADDRESS>
<STREET1>1221BROADWAY
<CITY>OAKLAND
<STATE>CA
<ZIP>94612
</MAIL-ADDRESS>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>rrd259272.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-12-04</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001338749</issuerCik>
        <issuerName>POTLATCH CORP</issuerName>
        <issuerTradingSymbol>PCH</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001184042</rptOwnerCik>
            <rptOwnerName>PEIROS LARRY</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>601 W. FIRST AVENUE, SUITE 1600</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SPOKANE</rptOwnerCity>
            <rptOwnerState>WA</rptOwnerState>
            <rptOwnerZipCode>99201</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Phantom Stock Units</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>31.64</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2009-12-04</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2054.362</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>31.64</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2054.362</value>
                    <footnoteId id="F3"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>11010.168</value>
                    <footnoteId id="F4"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Phantom stock units are credited to the reporting person's account on the transaction date in accordance with the provisions of the Potlatch Corporation Deferred Compensation Plan for Directors II and will be converted to cash and paid on a 1-for-1 basis with the issuer's common stock.</footnote>
        <footnote id="F2">Phantom stock units will be converted to cash and paid upon the reporting person's termination from service with Potlatch in accordance with the provisions of the Potlatch Corporation Deferred Compensation Plan for Directors II.</footnote>
        <footnote id="F3">Phantom stock unit beneficial ownership represents phantom stock allocated to the reporting person's Deferred Compensation Account since the reporting person's last report.  These phantom stock allocations represent an annual award grant.</footnote>
        <footnote id="F4">Includes phantom stock allocated to the reporting person's Deferred Compensation Account since the reporting person's last report that represents quarterly dividends.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Pamela A. Mull, Attorney-in-Fact</signatureName>
        <signatureDate>2009-12-08</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
