First Amendment to Employment Agreement

                                                                    Exhibit 10.6

                                 First Amendment
                                       to
                              Employment Agreement

     This First Amendment to Employment Agreement is made as of June 1, 2002,
and is by and between Vista Exploration Corporation., a Colorado corporation
("Employer"), and Xxxxxxx X. Xxxx, Xx., a resident of the State of Kansas
("Employee"). For good and valuable consideration, the receipt and sufficiency
of which are hereby acknowledged, the parties hereto, intending to be legally
bound, agree as follows:

     1. Section 2 of the Employment Agreement between Employer and Employee
dated as of April 1, 2002 (the "Agreement"), shall be amended and restated,
effective as of April 1, 2002, as follows:

     Professional Efforts. Employee shall devote such professional time and
     attention to the performance of his obligations under this Agreement as are
     reasonably required by Employer, and shall at all times perform all of his
     obligations hereunder to the best of his ability, experience and talent.

     2. Section 4 of the Agreement shall be amended and restated, effective as
of April 1, 2002, as follows:

     Compensation. In consideration for his services, Employer shall pay
     Employee a base salary at the rate of Thirty Thousand Dollars ($30,000) per
     annum. Employee's salary hereunder shall be payable in bi-monthly
     installments, or on such other payment schedule as is used to pay similarly
     situated employees of Employer. Employee shall be eligible for annual
     increases in base salary as determined by the Board of Directors of
     Employer in its sole discretion based upon Employee's performance and the
     financial performance of Employer. Employee agrees to defer the receipt of
     his salary for a period of (i) up to six (6) months; (ii) the Employer has
     received an additional Two Hundred Thousand Dollars ($200,000) in debt or
     equity capital infusion; (iii) the Employer starts receiving revenue from
     operations; or (iv) there is a change of control requiring an 8-K filing,
     whichever first occurs.

     3. Except as expressly set forth in this First Amendment, the Agreement
shall remain in full force and effect, enforceable in accordance with its terms.

EMPLOYEE:

/s/ Xxxxxxx X. Xxxx, Xx.
-------------------------
Xxxxxxx X. Xxxx, Xx.


EMPLOYER:

Vista Exploration Corporation

/s/ Xxxxxxx X. Xxxx, Xx.
------------------------
By: Xxxxxxx X. Xxxx, President