EXHIBIT NO. 5.1

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                          LOCKE PURNELL RAIN HARRELL (A
                       Professional Corporation) 2200 Ross
                               Avenue, Suite 2200
                               Dallas, Texas 75201
                                 (972) 740-8000

                                                  October 4, 1996

Comstock Resources, Inc.
5005 LBJ Freeway, Suite 1000
Dallas, Texas  75244

     Re:  Registration of 503,557 shares of Common Stock pursuant to a
          Registration Statement on Form S-3

Gentlemen:

     We have acted as counsel for Comstock Resources, Inc., a Nevada corporation
(the "Company"), in connection with the registration under the Securities Act of
1933, as amended (the "Securities Act"), pursuant to a Registration Statement on
Form S-3 (the "Registration Statement"), of 503,557 shares of Common Stock, $.50
par value,  of the Company (the "Common  Stock") to be issued to certain selling
shareholders  (the  "Selling  Shareholders")   identified  in  the  Registration
Statement upon exercise of certain stock options.

     We  have  made  such  inquiries  and  examined  such  documents  as we have
considered  necessary  or  appropriate  for the  purpose of giving  the  opinion
hereinafter set forth.  We have assumed the genuineness and  authenticity of all
signatures  on  all  original  documents,  the  authenticity  of  all  documents
submitted to us as  originals,  the  conformity  to  originals of all  documents
submitted  to us as copies and the due  authorization,  execution,  delivery  or
recordation of all documents where due  authorization,  execution or recordation
are prerequisites to the effectiveness thereof.

     Based upon the foregoing, having regard for such legal considerations as we
deem relevant,  we are of the opinion that the 503,557 shares of Common Stock to
be  issued  to the  Selling  Shareholders,  as  described  in  the  Registration
Statement,  have been duly authorized and, assuming receipt of the consideration
upon exercise of the options,  upon issuance will be legally issued,  fully paid
and nonassessable.

     We hereby  consent to the filing of this  opinion with the  Securities  and
Exchange  Commission  as  an  exhibit  to  the  Registration  Statement.  By  so
consenting,  we do not  thereby  admit that our firm's  consent is  required  by
Section 7 of the Securities Act.

                          Very truly yours,

                          LOCKE PURNELL RAIN HARRELL
                          (A Professional Corporation)

                          By: /s/JACK E. JACOBSEN
                          -----------------------
                                Jack E. Jacobsen


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