EXHIBIT 8.1

                        [LETTERHEAD OF MCGUIREWOODS LLP]

                               September 17, 2001

Board of Directors
Dominion Resources, Inc.
120 Tredegar Street
Richmond, Virginia 23219

Ladies and Gentlemen:
  Reference is made to the Registration Statement of Dominion Resources, Inc.,
a Virginia corporation ("Dominion"), on Form S-4 (the "Registration
Statement"), and the proxy statement/prospectus of Louis Dreyfus Natural Gas
Corporation, an Oklahoma corporation ("Louis Dreyfus") and Dominion contained
in the Registration Statement (the "Proxy Statement/Prospectus"), relating to
the merger of Louis Dreyfus with and into a wholly owned subsidiary of Dominion
(the "Merger"). We are acting as counsel to Dominion in connection with the
Merger and have participated in the preparation of the discussion set forth in
the section of the Proxy Statement/Prospectus entitled "The Merger--Material
U.S. Federal Income Tax Consequences of the Merger" (the "Discussion").

  We assume that the Merger and related transactions will be consummated in the
manner described in the Proxy Statement/Prospectus and in accordance with the
merger agreement, as amended and restated, attached thereto as Annex A (the
"Merger Agreement"). Subject to this assumption and to the assumptions and
qualifications set forth in the Discussion, it is our opinion that the
Discussion is accurate in all material respects. We note that our opinion is,
as described in the Discussion, premised upon the provision by us of a tax
opinion (the terms of which are set forth in Section 7.3(b) of the Merger
Agreement) anticipated to be delivered at or prior to closing of the Merger. We
express no other opinions as to the United States federal, state, local,
foreign, or other tax consequences of the Merger.

  We hereby consent to the filing of this opinion as Exhibit 8.1 to the
Registration Statement and to references to us under the heading "The Merger--
Material U.S. Federal Income Tax Consequences of the Merger" in the Proxy
Statement/Prospectus that is part of the Registration Statement, and in any
amendment or supplement to the Proxy Statement/Prospectus, and any related
registration statements filed pursuant to Rule 462(b) under the Act. We do not
admit by giving this consent that we are in the category of persons whose
consent is required under Section 7 of the Securities Act of 1993, as amended.

                                            Very truly yours,

                                            /s/ MCGUIREWOODS LLP