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                                                                     EXHIBIT 8.1


                            JACKSON WALKER, L.L.P.
                          1100 LOUISIANA, SUITE 4200
                             HOUSTON, TEXAS 77002
                          TELEPHONE:  (713) 752-4200
                          TELECOPIER: (713) 752-4221


                              September 28, 2001

Houston American Energy Corp.
801 Travis Street, Suite 1425
Houston, Texas 77002

Gentlemen:

     We have acted as counsel to Houston American Energy Corp., a Delaware
corporation ("HAEC") in connection with the proposed merger (the "Merger") of
Texas Nevada Oil & Gas Co., a Texas corporation ("TNOG") into HAEC pursuant to
the terms of that certain Plan and Agreement of Merger entered into between HAEC
and TNOG dated July 31, 2001, as amended and restated on September 26, 2001.
Capitalized terms used but not defined herein shall have the meanings assigned
to them in the Merger Agreement.

     In rendering this opinion we have examined such documents as we have deemed
relevant or necessary, including without limitation, the Merger Agreement.  In
our examination, we have assumed the genuineness of all signatures, the due
execution and delivery of all documents, the legal capacity of all natural
persons, the authenticity of all documents submitted to us as originals, the
conformity to original documents of all documents submitted to us as certified,
conformed or copies, and the authenticity of the originals of such copies.

     As to factual matters, in rendering this opinion, we have relied solely on
and have assumed the present and continuing truth and accuracy of the factual
representations and warranties contained in the Merger Agreement and related
documents and agreements.  The initial and continuing truth and accuracy of all
such factual matters constitutes an integral basis for, and a material condition
to, this opinion.

     Based upon our evaluation of the transaction, we do not believe that the
continuity of business enterprise requirement of Treas. Reg. 1.368-1(b) is met
in the Merger.  Continuity of business enterprise is a regulatory requirement
for a reorganization under Section 368(a) of the Internal Revenue Code of 1986
(the "Code").  In order to meet the continuity of business enterprise
requirement, HAEC must either (i) continue TNOG's historic business; or (ii) use
a significant portion of TNOG's historic business assets in a business.  See
Treas. Reg. (S)1.368-1(d)(1).  Under the Treasury Regulations, TNOG's historic
business is the business it has conducted most recently.  Treas. Reg. (S)1.368-
1(d)(2)(iii).

     It is our understanding that HAEC is entering into the Merger in order to
succeed to TNOG's status as a reporting company under the Securities and
Exchange Act of 1934 and to succeed to the shareholder base of TNOG.  While HAEC
intends to derive benefits from the prior activities of TNOG, these benefits are
not operating assets for purposes of the continuity of business enterprise
requirements, nor do these benefits constitute a line of TNOG's historic
business.  The Treasury Regulations provide that business assets may include
"intangible operating assets such as good will, patents, and trademarks . . ."
See Treas. Reg. (S)1.368(d)(3)(ii).

     Subject to the qualifications, assumptions and conditions stated above, and
because the continuity of business enterprise requirement is not met, we are of
the opinion that the Merger will not be treated for federal income tax purposes
as a reorganization within the meaning of Section 368(a) of the Code.  It is
likely that the Internal Revenue Service (the "Service") will assert that the
Merger constitutes a taxable sale of the assets of TNOG in exchange for the
shares of common stock delivered by HAEC under the Merger Agreement, any cash
paid to any shareholder of TNOG in connection with the Merger (collectively
referred to as the "Merger Property") and the amount of all liabilities of TNOG;
followed by the liquidation of TNOG, with the Merger Property distributed to the
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TNOG shareholders.  Under this characterization of the transaction, TNOG would
recognize taxable income to the extent that the sum of the fair market value of
the Merger Property and the liabilities of TNOG, exceed TNOG's adjusted tax
basis in its assets.  Each TNOG shareholder would recognize taxable gain or loss
to the extent that the fair market value of the Merger Property received by it
exceeds its adjusted basis in its TNOG stock.  The basis of each TNOG
shareholder in its HAEC common stock received in the Merger will be the fair
market value of the HAEC common stock at the date of distribution.  The holding
period for shares of HAEC received by TNOG shareholders in the Merger will not
include the holding period of their TNOG shares.  Houston American shareholders
will not recognize gain or loss.

     This opinion is based on the Code, the Income Tax Regulations promulgated
thereunder, judicial decisions and administrative pronouncements of the Service,
all as in effect on the date of this opinion and all of which are subject to
change at any time, possibly retroactively.  We undertake no obligation to you
or any other person to give notice of any such change.  This opinion is limited
strictly to the matters expressly stated herein and no other opinion may be
implied or inferred beyond such matters.  This opinion represents only our best
legal judgment and is not binding on the Service or the courts.

     This opinion is provided to you solely for use in connection with a
registration statement on Form S-4 to be filed by you with the Securities and
Exchange Commission.  We hereby consent to the filing of this opinion as an
exhibit to such registration statement.  This opinion shall not otherwise be
quoted or referred to in whole or in part in any report or document nor
furnished to any other person or entity other than your counsel or your
employees, except with our prior written consent or in response to a valid
subpoena or other lawful process.


                                        Very truly yours,


                                        /s/ Jackson Walker L.L.P.

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