<PAGE>
                                                                   Exhibit 10.39
                                JOINDER AGREEMENT

      JOINDER AGREEMENT dated as of November 25, 2002, by the undersigned, Lamar
Pinnacle Acquisition Co., (the "Additional Subsidiary Guarantor"), in favor of
JP Morgan Chase Bank, formerly The Chase Manhattan Bank, as administrative agent
for the Lenders party to the Credit Agreement referred to below (in such
capacity, together with its successors in such capacity, the "Administrative
Agent").

      Lamar Media Corp. (formerly Lamar Advertising Company), a Delaware
corporation (the "Borrower"), and certain of its subsidiaries (collectively, the
"Existing Subsidiary Guarantors" and, together with the Borrower, the "Securing
Parties") are parties to a Credit Agreement dated August 13, 1999 (as modified
and supplemented and in effect from time to time, the "Credit Agreement",
providing, subject to the terms and conditions thereof, for extensions of credit
(by means of loans and letters of credit) to be made by the lenders therein
(collectively, together with any entity that becomes a "Lender" party to the
Credit Agreement after the date hereof as provided therein, the "Lenders" and,
together with Administrative Agent and any successors or assigns of any of the
foregoing, the "Secured Parties") to the Borrower in an aggregate principal or
face amount not exceeding $1,000,000,000 (which, in the circumstances
contemplated by Section 2.01(d) thereof, may be increased to $1,400,000,000). In
addition, the Borrower may from time to time be obligated to one or more of the
Lenders under the Credit Agreement in respect of Hedging Agreements under and as
defined in the Credit Agreement (collectively, the "Hedging Agreements").

      In connection with the Credit Agreement, the Borrower, the Existing
Subsidiary Guarantors and the Administrative Agent are parties to the Pledge
Agreement dated September 15, 1999 (the "Pledge Agreement") pursuant to which
the Securing Parties have, inter alia, granted a security interest in the
Collateral (as defined in the Pledge Agreement) as collateral security for the
Secured Obligations (as so defined). Terms defined in the Pledge Agreement are
used herein as defined therein.

      To induce the Secured Parties to enter into the Credit Agreement, and to
extend credit thereunder and to extend credit to the Borrower under Hedging
Agreements, and for other good and valuable consideration the receipt and
sufficiency of which are hereby acknowledged, the Additional Subsidiary
Guarantor has agreed to become a party to the Credit Agreement and the Pledge
Agreement as a "Subsidiary Guarantor" thereunder, and to pledge and grant a
security interest in the Collateral (as defined in the Pledge Agreement).


      Accordingly, the parties hereto agree as follows:



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<PAGE>





      Section 1. Definitions. Terms defined in the Credit Agreement are used
herein as defined therein.

      Section 2. Joinder to Agreements. Effective upon the execution and
delivery hereof, the Additional Subsidiary Guarantor hereby agrees that it shall
become a "Subsidiary Guarantor" under and for all purposes of the Credit
Agreement and the Pledge Agreement with all the rights and obligations of a
Subsidiary Guarantor thereunder. Without limiting the generality of the
foregoing, the Additional Subsidiary Guarantor hereby:

                  (i) jointly and severally with the other Subsidiary Guarantors
            party to the Credit Agreement guarantees to each Secured Party and
            their respective successors and assigns the prompt payment in full
            when due (whether at stated maturity, by acceleration or otherwise)
            of all Guaranteed Obligations in the same manner and to the same
            extent as is provided in Article III of the Credit Agreement;

                  (ii) pledges and grants the security interests in all right,
            title and interest of the Additional Subsidiary Guarantor in all
            Collateral (as defined in the Pledge Agreement) now owned or
            hereafter acquired by the Additional Subsidiary Guarantor and
            whether now existing or hereafter coming into existence provided for
            by Article III of the Pledge Agreement as collateral security for
            the Secured Obligations and agrees that Annex 1 thereof shall be
            supplemented as provided in Appendix A hereto;

                  (iii) makes the representations and warranties set forth in
            Article IV of the Credit Agreement and in Article II of the Pledge
            Agreement, to the extent relating to the Additional Subsidiary
            Guarantor or to the Pledged Equity evidenced by the certificates, if
            any, identified in Appendix A hereto; and

                  (iv) submits to the jurisdiction of the courts, and waives
            jury trial, as provided in Sections 10.09 and 10.10 of the Credit
            Agreement.

      The Additional Subsidiary Guarantor hereby instructs its counsel to
deliver the opinions referred to in Section 6.10(a)(iii) of the Credit Agreement
to the Secured Parties.



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<PAGE>



      IN WITNESS WHEREOF, the Additional Subsidiary Guarantor has caused this
Joinder Agreement to be duly executed and delivered as of the day and year first
above written.

                                           Lamar Pinnacle Acquisition Co.


                                           By: /s/ Keith A. Istre
                                               ------------------------------
                                               Keith A. Istre
                                               Vice President - Finance and
                                               Chief Financial Officer

Attested:

By: James R. McIlwain
    --------------------------------
    James R. McIlwain, Secretary

Accepted and agreed:

JPMORGAN CHASE BANK,
formerly THE CHASE MANHATTAN BANK,
  as Administrative Agent

By: /s/ Joan M. Fitzgibbon
    ---------------------------------
    Title: Managing Director



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<PAGE>


The undersigned hereby respectively pledges and grants a security interest in
the Pledged Equity and evidenced by the certificate listed in Appendix A hereto
and agrees that Annex 1 of the above-referenced Pledge Agreement is hereby
supplemented by adding thereto the information listed on Appendix A.

The Lamar Company L.L.C., Issuee

By: /s/ Keith A. Istre
    --------------------------------------------
        Keith A. Istre
Title:  Vice President-Finance

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<PAGE>


Supplement to Annex 1
                                                 Appendix A to Joinder Agreement
<TABLE>
<CAPTION>
      Pledgor Ownership                    Issuer                  No. Shares      Cert. No.        %
<S>                            <C>                                 <C>             <C>             <C>
  The Lamar Company, L.L.C.    Lamar Pinnacle Acquisition Co.         1000             2           100
</TABLE>




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