<SUBMISSION>
<ACCESSION-NUMBER>0001186747-09-000029
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20091015
<FILING-DATE>20091019
<DATE-OF-FILING-DATE-CHANGE>20091019
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>BOYD GAMING CORP
<CIK>0000906553
<ASSIGNED-SIC>7990
<IRS-NUMBER>880242733
<STATE-OF-INCORPORATION>NV
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>3883 HOWARD HUGHES PARKWAY
<STREET2>NINTH FLOOR
<CITY>LAS VEGAS
<STATE>NV
<ZIP>89169
<PHONE>7027927200
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>3883 HOWARD HUGHES PARKWAY
<STREET2>NINTH FLOOR
<CITY>LAS VEGAS
<STATE>NV
<ZIP>89169
</MAIL-ADDRESS>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>BOYD GROUP
<DATE-CHANGED>19941130
</FORMER-COMPANY>
</ISSUER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>JOHNSON MARIANNE BOYD
<CIK>0001186742
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-12882
<FILM-NUMBER>091126892
</FILING-VALUES>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-10-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000906553</issuerCik>
        <issuerName>BOYD GAMING CORP</issuerName>
        <issuerTradingSymbol>BYD</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001186742</rptOwnerCik>
            <rptOwnerName>JOHNSON MARIANNE BOYD</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3883 HOWARD HUGHES PARKWAY</rptOwnerStreet1>
            <rptOwnerStreet2>NINTH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>LAS VEGAS</rptOwnerCity>
            <rptOwnerState>NV</rptOwnerState>
            <rptOwnerZipCode>89169</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Executive Vice President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-10-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>U</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>45000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
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                <transactionAcquiredDisposedCode>
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            <postTransactionAmounts>
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            <ownershipNature>
                <directOrIndirectOwnership>
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                <natureOfOwnership>
                    <value>By Limited Partnership *</value>
                    <footnoteId id="F3"/>
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        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
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                <transactionFormType>4</transactionFormType>
                <transactionCode>U</transactionCode>
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            <transactionTimeliness>
                <value></value>
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                <transactionShares>
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            <postTransactionAmounts>
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            <ownershipNature>
                <directOrIndirectOwnership>
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                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Limited Partnership *</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
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        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
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            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
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                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trust</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>722353</value>
                </sharesOwnedFollowingTransaction>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
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                <natureOfOwnership>
                    <value>By Limited Partnership *</value>
                    <footnoteId id="F5"/>
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        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
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                </sharesOwnedFollowingTransaction>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Limited Partnership *</value>
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        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
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            <postTransactionAmounts>
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            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Limited Partnership *</value>
                    <footnoteId id="F7"/>
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            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
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                <sharesOwnedFollowingTransaction>
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                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
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                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Limited Partnership *</value>
                    <footnoteId id="F8"/>
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            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
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            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1552049</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Limited Partnership *</value>
                    <footnoteId id="F9"/>
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        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>53904</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Annuity *</value>
                    <footnoteId id="F10"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>108340</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Annuity *</value>
                    <footnoteId id="F11"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>30582</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Annuity *</value>
                    <footnoteId id="F12"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>32613</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Annuity *</value>
                    <footnoteId id="F13"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>62218</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Annuity *</value>
                    <footnoteId id="F14"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>123587</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Annuity *</value>
                    <footnoteId id="F15"/>
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            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>30011</value>
                </sharesOwnedFollowingTransaction>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trust *</value>
                    <footnoteId id="F16"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>30011</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trust *</value>
                    <footnoteId id="F17"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>28721</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trust *</value>
                    <footnoteId id="F18"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>30011</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trust *</value>
                    <footnoteId id="F19"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>30011</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trust *</value>
                    <footnoteId id="F20"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>28521</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trust *</value>
                    <footnoteId id="F21"/>
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        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
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            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>14613</value>
                </sharesOwnedFollowingTransaction>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trust *</value>
                    <footnoteId id="F22"/>
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            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>91324</value>
                </sharesOwnedFollowingTransaction>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trust *</value>
                    <footnoteId id="F23"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>130247</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trust *</value>
                    <footnoteId id="F24"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>69934</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The reporting person, her father and her brothers formed a family limited partnership, BG-09 Limited Partnership (&quot;BG-09).  Entities controlled by the reporting person, her father and her brothers are the limited partners of BG-09, and each of the William S. Boyd Gaming Properties Trust (&quot;WSBGPT&quot;) and the Marianne Boyd Gaming properties Trust (&quot;MBGPT&quot;) are the general partners of BG-09.  In connection with the formation of BG-09: (A) On October 19, 2009 WSBGPT contributed 900,000 shares of Boyd Gaming common stock and received an 84% limited partnership interest and a 1% general partnership interest, and the William R. Boyd Gaming Properties Trust contributed 45,000 shares of Boyd gaming common stock and received a 5% limited partnership interest; and (B) On October 15, 2009 the Samuel J. Boyd Gaming Properties Trust contributed 45,000 shares of Boyd Gaming common stock and received a 5% limited partnership interest.  Continued on Footnote 2.</footnote>
        <footnote id="F2">In addition, in connection with the formation of BG-09, on October 19, 2009, MBGPT contributed 45,000 shares of Boyd Gaming common stock to BG-09 and received a 4% limited partnership interest and a 1% general partnership interest.  The effect of the contribution of the 45,000 shares of Boyd Gaming common stock to BG-09 by MBGPT was a change in one form of indirect beneficial ownership by the reporting person to another form of indirect beneficial ownership by the reporting person.  Marianne Boyd Johnson is the trustee, settlor and beneficiary of MBGPT.  *</footnote>
        <footnote id="F3">By BG-09 Limited Partnership</footnote>
        <footnote id="F4">By the Marianne Boyd Gaming Properties Trust, of which the reporting person is the Trustee, Settlor and Beneficiary, excluding shares held by W.M. Limited Partnership, BG-99 Limited Partnership, BG-00 Limited Partnership, BG-01 Limited Partnership and BG-09 Limited Partnership.</footnote>
        <footnote id="F5">By the W.M. Limited Partnership</footnote>
        <footnote id="F6">By the BG-99 Limited Partnership</footnote>
        <footnote id="F7">Bt BG-00 Limited Partnership</footnote>
        <footnote id="F8">By BG-01 Limited Partnership</footnote>
        <footnote id="F9">By BG-02 Limited Partnership</footnote>
        <footnote id="F10">By the BG-01 Grantor Retained Annuity Trust 2 (&quot;BG-01 GRAT 2&quot;), of which the reporting person is the trustee.</footnote>
        <footnote id="F11">By the BG-01 Grantor Retained Annuity Trust # (&quot;BG-01 GRAT 3&quot;), of which the reporting person is the trustee.</footnote>
        <footnote id="F12">By the BG-99 Grantor Retained Annuity Trust 3 (&quot;BG-99 GRAT 3&quot;), of which the reporting person is the trustee.</footnote>
        <footnote id="F13">By the BG-00 Grantor Retained Annuity Trust 3 (&quot;BG-00 GRAT 3&quot;), of which the reporting person is the trsutee.</footnote>
        <footnote id="F14">By the BG-02 Grantor Retained Annuity Trust 2 (&quot;BG-02 GRAT 2&quot;), of which the reporting person is the trustee.</footnote>
        <footnote id="F15">By the BG-02 Grantor Retained Annuity Trust 3 (&quot;BG-02 GRAT 3&quot;), of which the reporting person is the trustee.</footnote>
        <footnote id="F16">By the Aysia Lynn Boyd Education Trust, dated July 1, 1997, of which the reporting person is the trustee.</footnote>
        <footnote id="F17">By the Taylor Joseph Boyd Education Trust, dated July 1, 1997, of which the Reporting Person is the trustee.</footnote>
        <footnote id="F18">By the William Samuel Boyd Education Trust, dated July 1, 1997, of which the Reporting Person is the trustee.</footnote>
        <footnote id="F19">By the Samuel Joseph Boyd, Jr. Education Trust, dated July 1, 1997, of which the Reporting Person is the trustee.</footnote>
        <footnote id="F20">By the T-Mir Kathleen Boyd Education Trust, dated July 1, 1997, of which the Reporting person is the trustee.</footnote>
        <footnote id="F21">By the Josef William Boyd Education Trust, dated July 1, 1997, of which the Reporting Person is the trustee.</footnote>
        <footnote id="F22">By the Jusin Boyd Education Trust dated November 1, 1999, of which the Reporting Person is the trustee.</footnote>
        <footnote id="F23">By the Johnson Children's Trust, dated June 24, 1996, Bruno Mark, trustee.</footnote>
        <footnote id="F24">William R. Boyd and Myong Boyd Children's Trust dated August 1, 1993, of which the Reporting Person is trustee.</footnote>
    </footnotes>

    <remarks>* The reporting person expressly disclaims beneficial ownership of any securities of the Issuer except to the extent of the reporting person's pecuniary interest in a trust, partnership or other entity which owns such securities.</remarks>

    <ownerSignature>
        <signatureName>Brian Larson, Attorney-in-Fact of Marianne Boyd Johnson</signatureName>
        <signatureDate>2009-10-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
