EXHIBIT 3.23


                          CERTIFICATE OF INCORPORATION
                                       OF
                         TESORO HYDROCARBONS COMPANY USA


                  1. The name of the corporation is:

                         TESORO HYDROCARBONS COMPANY USA

                  2. The address of its registered offices in the State of
         Delaware is Corporation Trust Center, 1209 Orange Street, in the City
         of Wilmington, County of New Castle. The name of its registered agent
         at such address if The Corporation Trust Company.

                  3. The nature of the business or purposes to be conducted or
         promoted is to engage in any lawful act or activity for which
         corporations may be organized under the General Corporation Law of
         Delaware.

                  4. The total number of shares of all classes of stock which
         the corporation shall be authorized to issue is one thousand (1,000)
         shares of common stock, $1.00 par value.

                  5. A director of the corporation is not liable to the
         corporation or its stockholders for monetary damages for breach of
         fiduciary duty as a director, except that this article does not
         eliminate or limit the liability of a director: (i) for any breach of
         the director's duty of loyalty to the corporation or its stockholders;
         (ii) for acts or omissions not in good faith or which involve
         intentional misconduct or a knowing violation of law; (iii) under
         Section 174 of the General Corporation Law of Delaware; or (iv) for any
         transaction from which the director derived an improper personal
         benefit.

                  6. The board of directors is authorized to make, alter or
         repeal the by-laws of the corporation. Election of directors need not
         be by written ballot.

                  7. The name and mailing address of the incorporator is:

                                  M. A. Brzoska
                          The Corporation Trust Company
                               1209 Orange Street
                           Wilmington, Delaware 19901

         I, the undersigned, as incorporator and for the purpose of forming a
corporation pursuant to the General Corporation Law of Delaware, do make this
certificate, hereby declaring and certifying that this is my act and deed and
the facts herein stated are true, and accordingly have hereunto set my hand this
10th day of June, 1999.

                                               /s/ M.A. Brzoska
                                             ------------------
                                             M. A. Brzoska






                         CERTIFICATE OF AMENDMENT OF THE
                          CERTIFICATE OF INCORPORATION
                                       OF
                         TESORO HYDROCARBONS COMPANY USA


         Tesoro Hydrocarbons Company USA, a corporation organized under and
existing by virtue of the General Corporation Law of the State of Delaware, does
hereby certify:

         FIRST: That by the written consent of all members of the Board of
Directors of Tesoro Hydrocarbons Company USA, dated July 6, 2001, and filed with
the minutes of proceedings of said Board of Directors, the Board of Directors of
said corporation duly adopted a resolution proposing and declaring advisable a
certain amendment to the Certificate of Incorporation of said corporation, and
directing that such amendment be submitted for consideration to the shareholder
of said corporation. The resolution of the Board of Directors setting forth the
proposed amendment is as follows:

         RESOLVED, that the Board of Directors declares it advisable and
         proposes that Article 1 of the Certificate of Incorporation of Tesoro
         Hydrocarbons Company USA be amended so as to read in its entirety as
         follows:

            "The name of the corporation is Tesoro Aviation Company."

         SECOND: That by written consent of the sole shareholder of said
corporation dated July 6, 2001, and filed with the minutes of proceedings of
said shareholder, the shareholder voted in favor of said amendment.

         THIRD: That said amendment was duly adopted in accordance with the
provisions of Section 242 of the General Corporation Law of the Sate of
Delaware.

         FOURTH: That the capital of said corporation will not be reduced under
or by reason of said amendment.

         IN WITNESS WHEREOF, said Tesoro Hydrocarbons USA has caused this
certificate to be signed by Bruce A. Smith, its President, and attested by James
C. Reed, Jr., its Executive Vice President, General Counsel and Secretary, this
6th day of July, 2001.

ATTEST:                                      Tesoro Hydrocarbons Company USA


 /s/ James C. Reed, Jr.                       /s/ Bruce A. Smith
------------------------------               --------------------------------
James C. Reed, Jr.                           Bruce A. Smith
Executive Vice President                     President
General Counsel and Secretary