<PAGE>   1
                                                                     EXHIBIT 3.1

                           ARTICLES OF INCORPORATION

                                       OF

                           HYDRO NUCLEAR CORPORATION

     We, the undersigned natural persons of the Age of twenty-one years or
more, acting as incorporators of a corporation under the New Mexico Business
Corporation Act, adopt the following Articles of Incorporation for such
corporation:

                                   ARTICLE I.

     The name of the corporation shall be: HYDRO NUCLEAR CORPORATION.

                                  ARTICLE II.

     The period of its duration is perpetual.

                                  ARTICLE III.

     The purpose for which this corporation is organized is to engage in all
phases of mining, exploration, leaching, purchase and sale of any and all
minerals of all types, to engage in all other activities related to such
business, and to engage in and do any lawful act concerning any or all lawful
business for which corporations may be organized under the laws of New Mexico,
now or hereafter in affect.

                                  ARTICLE IV.

     The aggregate number of shares which the corporation shall have authority
to issue are as follows:

     (a)  5,000,000 shares of common stock, each share having a par value of
          10 cents; and

     (b)  5,000,000 shares of preferred stock, each share having a par value of
          10 cents, the designations, preferences, and relative participating,
          optional or other special rights, qualifications, limitations or
          restrictions with respect to such shares, including whether or not
          the preferred shares are convertible into shares of common stock, to
          be determined in a Resolution or Resolutions providing for the issue
          of such stock adopted by the Board of Directors.

                                   ARTICLE V.

     Cumulative voting of shares shall not be permitted.
<PAGE>   2
                                  ARTICLE VI.

     The corporation will not commence business until consideration of the
value of at least one thousand dollars ($1,000) has been received for the
issuance of shares.

                                  ARTICLE VII.

     Shareholders shall not have pre-emptive rights to acquire additional or
treasury shares of the corporation. All lawful restrictions on the sale or
other disposition of shares may be placed upon all or a portion or portions of
the certificates evidencing the corporation's shares. No shareholder or
subscriber to the capital stock of the corporation shall be under any
obligation to the corporation or its creditors with respect to such stock other
than the obligation to pay the corporation the full consideration for which
stock was issued or is to be issued.

                                 ARTICLE VIII.

     The address of the initial registered office is 457-J Washington, S.E.,
Albuquerque, New Mexico, 87108 and the name of its initial registered agent at
such address is Malcolm G. Colberg.

                                  ARTICLE IX.

     The address of the corporation's place of business is Suite 1400 "G", First
National Bank Building, East, Albuquerque, New Mexico, 87108.

                                   ARTICLE X.

     The names and post office addresses of the incorporators are as follows:

                            MALCOLM G. COLBERG
                            457-J Washington SE
                            Albuquerque, New Mexico
                                        
                            GEORGE O. LOTSPEICH
                            609 Sycamore NE
                            Albuquerque, New Mexico
                                        
                            ROBERT R. HURST
                            1400 Virginia NE, Apt. #77
                            Albuquerque, New Mexico
                                        
                            J. DOUGLAS HENRY
                            1015 Cardenas SE, Apt. #5
                            Albuquerque, New Mexico




                                     - 2 -
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                                  ARTICLE XI.


     The affairs of the corporation shall be conducted by a Board of Directors
and such officers as the Directors may elect or appoint. The number of
Directors constituting the initial Board of Directors of the corporation is
four, and the names and post office addresses of the persons who are to serve
as Directors until the first annual meeting of shareholders or special meeting
called for the election of Directors, and until their successors are elected and
shall qualify are:

          Name                               Address
---------------------------        -----------------------------

Malcolm G. Colberg                 457-J Washington SE
                                   Albuquerque, New Mexico

George O. Lotspeich                609 Sycamore NE
                                   Albuquerque, New Mexico

Robert R. Hurst                    1400 Virginia NE, Apt. #77
                                   Albuquerque, New Mexico

J. Douglas Henry                   1015 Cardenas SE, Apt. #5
                                   Albuquerque, New Mexico

The number of Directors to be elected at the annual meeting of shareholders or
at any specific meeting called for the election of Directors shall not be less
than three or more than seven, the exact number to be fixed by the By-Laws. All
directorships to be filled by reason of an increase in the number of Directors
shall be filled by election at an annual meeting or at a special meeting of
shareholders called for that purpose.



                                  ARTICLE XII.

     Shareholders shall not have pre-emptive rights to acquire additional or
treasury shares of the corporation. All lawful restrictions on the sale or
other disposition of shares may be placed upon all or a portion or portions of
the certificates evidencing the corporation's shares. No shareholder or
subscriber to the capital stock of the corporation shall be under any
obligation to the corporation or its creditors with respect to such stock other
than the obligation to pay the corporation the full consideration for which
stock was issued or is to be issued.




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                                 ARTICLE XIII.


     Shareholders shall be entitled to one vote per share upon each matter
submitted to a vote at a meeting of the shareholders. One-third of the shares
entitled to vote, represented in person or by proxy, shall constitute a quorum
at a meeting of shareholders.

                                  ARTICLE XIV.

     The officers, Directors and other members of management of this
corporation shall be subject to the doctrine of corporate opportunities only
insofar as it applies to business opportunities in which this corporation has
expressed an interest as determined from time to time by the corporation's Board
of Directors as evidenced by resolutions appearing in the corporation's Minutes.
When such areas of interest are delineated, all such business opportunities
within such areas of interest which come to the attention of the officers,
Directors and other members of management of this company shall be disclosed
promptly to this corporation and made available to it. The Board of Directors
may reject any business opportunity presented to it and thereafter any officer,
Director or other member of management may avail himself of such opportunity.
Until such time as this corporation, through its Board of Directors, has
designated an area of interest, the officers, Directors and other members of
management of this corporation shall be free to engage in such areas of interest
on their own and this doctrine shall not limit the rights of any officer,
Director or other member of management of this corporation to continue a
business existing prior to the time that such area of interest is designated by
this corporation. This provision shall not be construed to release any employee
of the corporation (other than an officer, Director or member of management)
from any duties which he may have to the corporation.

                                  ARTICLE XV.

     No contract or other transaction between this corporation and any other
corporation, whether or not a majority of the shares of the capital stock of
such other corporation is owned by this corporation, and no act of this
corporation shall be in any way affected or invalidated by the fact that any of
the Directors, officers or other members of the management of this corporation
are pecuniarily or otherwise interested in or are Directors, officers or members
of management of such other corporation. Any Director, officer or other member
of management of this corporation individually, or any firm of which such
Director, officer or member of management may be a member, may be a party to, or
may be pecuniarily or otherwise interested in, any contract or transaction of
this corporation, provided, however, that the fact that he or such firm is so
interested shall be disclosed or shall have been known to the Board of Directors
of this corporation or a majority thereof; and any Director of this corporation
who is also a Director,


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officer or member of management of such other corporation, or who is so
interested, may be counted in determining the existence of a quorum at any
meeting of the Board of Directors of this corporation that shall authorize such
contract or transaction, and may vote thereat to authorize such contract or
transaction, with like force and effect as if he were not such Director, officer
or member of management of such other corporation or not so interested.

                                        ARTICLE XVI.

     The corporation shall indemnify each Director and each officer, his heirs,
executors and administrators, against expenses reasonably incurred or liability
incurred by him in connection with any action, suit or proceeding to which he
may be made a party by reason of his being or having been a Director or officer
of the corporation, except in relation (i) to matters as to which he shall be
finally adjudged in such action, suit or proceeding to be liable for fraud or
misconduct, and (ii) to liabilities under the Securities Act of 1933, as
amended, or other applicable securities laws. In the event of a settlement
before or after action or suit, indemnification shall be provided only in
connection with such matters covered by the settlement as to which the
corporation is advised by counsel that the person to be indemnified was not
guilty of such fraud or misconduct. The foregoing right of indemnification shall
not exclude other rights to which he may be entitled.

                                        ARTICLE XVII.

     The Board of Directors of this corporation is authorized to adopt, confirm,
ratify, alter, amend, rescind and repeal By-Laws or any portion thereof from
time to time.

     DATED May 14, 1969

                                           /s/ MALCOLM G. COLBERG
                                        ----------------------------
                                           Malcolm G. Colberg

                                           /s/ GEORGE O. LOTSPEICH
                                        -----------------------------
                                           George O. Lotspeich

                                           /s/ ROBERT R. HURST
                                        ------------------------------
                                           Robert R. Hurst

                                           /s/ J. DOUGLAS HENRY
                                        ------------------------------
                                           J. Douglas Henry




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STATE OF NEW MEXICO      )
                         )ss.
COUNTY OF BERNALILLO     )

     The foregoing instrument was acknowledged before me this 14 day of May,
1969, by Malcolm G. Colberg, George O. Lotspeich, Robert R. Hurst, and J.
Douglas Henry.
                                           /s/ [ILLEGIBLE]
                                        ------------------------------
                                             Notary Public

     SEAL

        My commission expires:
          June 30, 1971





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                                                          FILED IN OFFICE OF
                                                    STATE CORPORATION COMMISSION
                                                            OF NEW MEXICO

                                                             JUN 30 1977

                                                           CORPORATION AND
                                                         FRANCHISE TAX DEPTS.


                     AMENDMENT TO ARTICLES OF INCORPORATION
                                       OF
                           HYDRO NUCLEAR CORPORATION


          1.   The name of the corporation is Hydro Nuclear Corporation.

          2.   The amendment so adopted is:  Change of name, Hydro Nuclear
Corporation to Cobb Nuclear Corporation.

          3.   This amendment was adopted by the shareholders on June 17, 1977.

          4.   There are 934,498 shares outstanding and entitled to vote.

          5.   670,779 shares voted for the change of name, and 625 shares cast
against the change.

                                             /s/ GEORGE O. LOTSPEICH
                                             ----------------------------------
                                             GEORGE O. LOTSPEICH, President


                                             /s/ MALCOLM G. COLBERG
                                             ----------------------------------
                                             MALCOLM G. COLBERG, Secretary


                            V E R I F I C A T I O N

          MALCOLM G. COLBERG being first duly sworn on oath, STATES:  That he
is the Secretary of Hydro Nuclear Corporation, that he knows the contents of
the Articles of Amendment which he has fully read and the matters stated
therein are true and correct.

                                             /s/ MALCOLM G. COLBERG
                                             ----------------------------------
                                             MALCOLM G. COLBERG

          SUBSCRIBED AND SWORN to before me this 27th day of June, 1977.


                                             /s/ D. CALLAHAN
                                             ----------------------------------
                                             NOTARY PUBLIC

My Commission Expires:

       4-23-78
----------------------
                                     RECEIVED

                                   JUN 30 1977

                               N.M. ST. CORP. COMM.
                            Corp./Franchise Tax Depts.
<PAGE>   8
                                                          FILED IN OFFICE OF
                                                    STATE CORPORATION COMMISSION
                                                             OF NEW MEXICO
                                                  
                                                             JUN 30 1977

                                                           CORPORATION AND 
                                                         FRANCHISE TAX DEPTS.
                                                  
                                 CERTIFICATION
                                                         
                                                         

     I hereby certify that the copy of the Minutes attached hereto is a true
and correct copy of the Annual Stockholders' Meeting of June, 17, 1977.


                                             /s/ MALCOLM G. COLBERG
                                             ----------------------------------
                                             MALCOLM G. COLBERG, Secretary



                                                              RECEIVED

                                                            JUN 30 1977

                                                         N.M. ST. CORP. COMM.
                                                      Corp./Franchise Tax Depts.
<PAGE>   9
                             ARTICLES OF AMENDMENT

                                     TO THE

                           ARTICLES OF INCORPORATION

                                       OF

                            COBB NUCLEAR CORPORATION


          Pursuant to the provisions of the New Mexico Business Corporation
Act, the undersigned corporation adopts the following Articles of Amendment to
its Articles of Incorporation:

          FIRST:  The name of the corporation is COBB NUCLEAR CORPORATION.

          SECOND:  The following amendments to the Articles of Incorporation
were adopted by the Shareholders of the corporation at the Annual Meeting of
Shareholders held on December 19, 1980, in the manner prescribed by the New
Mexico Business Corporation Act:

                (1)  Article I hereby is repealed and a new Article I is
          adopted as follows:

                                   ARTICLE I.

                The name of the corporation is Cobb Resources Corporation.

                (2)  Article IV hereby is repealed and a new Article IV is
          adopted as follows:

                                  ARTICLE IV.

                The aggregate number of shares which the corporation shall have
          authority to issue are as follows:

                (a)  25,000,000 shares of common stock, each share having a par
                     value of $0.10; and

                                                              RECEIVED

                                                             JUN 29 1981

                                                         N.M. ST. CORP. COMM.
                                                      Corp./Franchise Tax Depts.
<PAGE>   10
          (b)  5,000,000 shares of preferred stock, each share having a par
               value of $0.10, the designations, preferences, and relative
               participating, optional or other special rights, qualifications,
               limitations or restrictions with respect to such shares,
               including whether or not the preferred shares are convertible
               into shares of common stock, to be determined in a Resolution or
               Resolutions providing for the issue of such stock adopted by the
               Board of Directors.

      THIRD:   The number of shares of the corporation outstanding at the time
such Amendment was adopted was 2,425,053, and the number of shares entitled to
vote thereon was 2,425,053.

     FOURTH:   The corporation has only one class of stock outstanding, it
being $0.10 par value common stock.

     FIFTH:    The number of shares voted as regards such Amendments were as
follows:

     (1)   Change of Name:  For:  1,965,898; Against:  100; Abstain:  767.

     (2)   Increase in Authorized Common Stock:  For:  1,962,997; Against:
           3,368; Abstain:  400.

     SIXTH:    The Amendments do not provide for an exchange, reclassification
or cancellation of issued shares.

     SEVENTH:  The Amendments do not effect a change in the amount of stated
capital.

     Dated:  January 2, 1981
            -----------------
                                             COBB NUCLEAR CORPORATION
                                             a New Mexico corporation


                                             By  /s/ GEORGE O. LOTSPEICH
                                                 ------------------------------
                                                 George O. Lotspeich, President

S E A L

Attest:

/s/ MALCOLM G. COLBERG
-------------------------------
Malcolm G. Colberg, Secretary

                                     - 2 -
<PAGE>   11
STATE OF NEW MEXICO      )
                         ) ss.
COUNTY OF BERNALILLO     )


     On January 2, 1981, before me, Doris A. Lake, a Notary Public in and for
said county and state, personally appeared George O. Lotspeich, who acknowledged
before me that he is President of Cobb Nuclear Corporation, a New Mexico
corporation, and that he signed the foregoing Articles of Amendment as his free
and voluntary act and deed for the uses and purposes therein set forth.

     IN WITNESS WHEREOF I have hereunto set my hand and seal on January 2, 1981.

     My commission expires:

            6-21-81

                                                  /s/ DORIS A. LAKE
                                                  ------------------------------
                                                  Notary Public