<PAGE>


                          OPTION TO PURCHASE AGREEMENT
                           (UNPATENTED MINING CLAIMS)
                            WILDCAT PROJECT, NEVADA

This Option to Purchase Agreement (hereinafter "Agreement") is made and entered
effective September 23, 2003, by and between Monex Exploration, a partnership,
whose partners are E.Chapel and Deborah H.Shields (hereinafter "Owner"), whose
address is 5195 Rio Pinar, Reno, Nevada 89509 and Vista Nevada Corp., a Nevada
corporation (hereinafter "Vista"), whose address is 7961 Shaffer Parkway,
Suite 5, Littleton, Colorado 80127.

RECITALS

Owner represents that it is the owner and is in possession of all those certain
unpatented mining claims situated in Pershing County, Nevada, which are more
particularly described in Exhibit "A" attached hereto and made a part hereof,
together with all ore, minerals, and mineral substances of every nature and
character, whatsoever, and together with all dips, spurs, extralateral rights,
dumps, tailings, severed ore thereon, and any easements, rights-of-way, water
rights, structures, improvements, and fixtures appurtenant thereto, (hereinafter
"Premises"), and all rights hereafter acquired by Owner to the Premises.

Vista desires to obtain and Owner is willing to grant an exclusive option to
purchase the Premises to Vista, together with certain rights of access to the
Premises during the term of this Agreement as hereinafter set forth.

NOW, THEREFORE, in consideration of Ten Dollars ($10.00) and other good and
valuable consideration paid to Owner, the receipt and sufficiency of which are
hereby acknowledged, and further in consideration of the mutual covenants,
agreements, and promises herein contained, the parties hereto agree as follows:

1.0  GRANT OF RIGHTS AND OPTION.

     (a)  Owner hereby grants to Vista free and unrestricted access to the
          Premises, the exclusive option to purchase the Premises, and the
          exclusive right (i) to explore, sample, and test the Premises, (ii) to
          erect, construct, use, and maintain on the Premises such roads,
          structures, machinery, equipment, personal property, fixtures, and
          improvements as may be required for the conduct of its exploration and
          related operations, and (iii) to extract and remove from the Premises
          such ore, minerals, or mineral substances as may be removed in the
          normal course of exploration operations and such materials as Vista
          may require for bulk sampling and testing. Vista shall not conduct
          commercial mining operations on the Premises or sell any ore,
          minerals, or other products from the Premises before exercising the
          Option to Purchase as provided for in this Agreement.

     (b)  To exercise all other rights which are incidental to any and all of
          the rights referred to herein; and

     (c)  To use the Premises for all of the purposes stated in this Section in
          conjunction with



<PAGE>


     Vista's activities on other properties.

2.0  TERM.

2.1  TERM OF AGREEMENT. This Agreement is granted for a term of one (1) year
     from the date hereof and, provided that Vista exercises its Option to
     Purchase before the end of the one year term, for an additional period for
     the Closing provided for in Section 4.3 to occur.

3.0  OPTION PAYMENTS.

     (a)  Vista shall pay to Owner option payments (hereinafter "Option
          Payments") on the dates and in the amounts as follows:

          <TABLE>
          <CAPTION>
          Amounts                 Due Dates
          -------                 ---------
          <S>                     <C>
          $ 200,000               Upon the execution of this Agreement
          $ 300,000               on or before August 15, 2004.
          </TABLE>

          If this Agreement is terminated, Vista shall have no obligation to
          make any of the payments described above, the due dates of which occur
          after the date of such termination.

          These payments shall be in lieu of any obligation on the part of Vista
          express or implied, to explore the Premises or perform any work
          thereon except as may otherwise be expressly provided for in this
          Agreement.

     (b)  Credit/Offset. All Option Payments paid to Owner shall be a credit
          against the Purchase Price as provided in Section 4.1.

3.1  PAYMENT METHOD. All payments due to the Owner shall be paid by check or
     wire transfer. All payments shall be made to the Owner at the address
     specified in Section 10.3 (NOTICES). Owner may designate a different
     receiving address or account consistent with the terms of Section 10.3.

4.0  PURCHASE OPTION. Owner hereby grants to Vista the exclusive right and
     option to purchase all of the Premises from Owner at anytime during the
     term of this Agreement. Vista shall be required to exercise its option to
     purchase all of the Premises before the commencement of construction of any
     permanent facilities for mining or processing ore minerals, and mineral
     substances on the Premises or the commencement of any actual mining
     operations on the Premises for the purpose of beginning commercial
     production of minerals from the Premises.

4.1  PURCHASE PRICE. The Purchase Price for all of the Premises, together with
     any and all easements, rights-of-way, water rights, structures,
     improvements and fixtures appurtenant thereto (hereinafter "Purchase
     Price") shall be Five Hundred Thousand Dollars ($500,000).


                                       2
<PAGE>


4.2  EXERCISE OF PURCHASE OPTION. Vista may exercise the Purchase Option at any
     time during the term of the Agreement. To exercise the Purchase Option,
     Vista shall either (i) deliver written notice to Owner; or (ii) mail
     written notice to Owner at the address shown first above.

     In the event Vista purchases the Premises, Vista shall pay the Purchase
     Price to Owner and Owner shall execute and deliver the Mining Deed to Vista
     as provided in Section 4.3. Thereafter, Vista shall own all of Owner's
     right, title, and interest in and to the Premises.

4.3  CLOSING. If Vista exercises the Option, the parties shall diligently
     attempt to close the purchase and sale of the Property within thirty (30)
     days following Vista's delivery of its notice of exercise. Owner shall
     execute and deliver at the Closing a Mining Deed in form proper for
     recording under Nevada law. The Mining Deed shall convey from Owner to
     Vista all of Owner's right, title and interest in and to the Premises,
     together with all dumps, tailings, extralateral rights, minerals (including
     severed ore), mineral rights, water rights and all easements, fixtures,
     improvements, rights-of-way, structures and water rights on, under or
     appurtenant to the Premises, subject only to the existing production
     royalties reserved to Raymond W. Wittcopp and Leslie A. Wittcopp and LAC
     Minerals (USA) Inc. and Homestake Mining Company, the latter two companies
     being affiliates of and presently controlled or owned by Barrick Gold
     Corporation. Owner's conveyance under the Mining Deed shall also be subject
     to the obligation of VISTA AND ITS SUCCESSORS AND ASSIGNS to pay to Owner a
     one-time production payment in the amount of $500,000.00 upon commencement
     of commercial production of minerals from the Premises. For purposes of the
     Mining Deed, the term "commercial production" shall mean the production of
     minerals in commercial quantities for shipment from the Premises and sale,
     but not including minerals produced for testing, including bulk samples.
     The Mining Deed shall include Owner's general warranty of title to Vista,
     subject to the foregoing production royalties and subject to the paramount
     title of the United States to the unpatented mining claims, free and clear
     of any and all liens, claims and encumbrances of every kind and nature,
     except those described in this paragraph. At the Closing, Vista shall
     deliver the Purchase Price in immediately available funds or by wire
     transfer to an account designated by Owner. The parties shall execute and
     deliver such other written assurances as are reasonably necessary to
     consummate the transactions contemplated under this Agreement and to
     complete the Closing. Vista shall pay the real property transfer taxes,
     recording fees and Bureau of Land Management notice of transfer filing fees
     incurred on the recording of the Mining Deed and filing of the notice of
     transfer with the Bureau of Land Management. The real property taxes, if
     any, assessed against the Premises shall be prorated between Owner and
     Vista as of the Closing Date. On completion of the Closing, Vista shall own
     all right, title and interest in and to the Premises, subject only to the
     production royalties and production payment obligation described in this
     paragraph.

     Closing shall be accomplished at a location mutually acceptable to both
     parties within thirty (30) days of notice of exercise of the Purchase
     Option ("Closing Date").



                                       3
<PAGE>


5.0  OWNER'S RIGHTS. COVENANTS. AND OBLIGATIONS.

5.1  OWNER'S WARRANTIES. Owner covenants, warrants, and represents that as of
     the effective date of this Agreement and as of the date of the Closing
     provided for in Section 4.3, which covenants, warranties and
     representations shall survive the Closing:

     (a)  Owner owns the entire undivided title and interest in and to the
          Premises, except for paramount title in the United States as to the
          unpatented mining claims included in the Premises, that Owner is in
          possession of the Premises, that all required corporate authorizations
          have been obtained to give Owner the full power and authority to enter
          into this Agreement, that Owner knows of no other person claiming any
          interest in the Premises or the ground covered thereby, and that the
          Premises is free from all leases, liens, encumbrances, and outstanding
          adverse claims and interests.

     (b)  Vista, in its sole discretion, may take any action reasonably
          necessary, including commencement of legal proceedings, to remove any
          clouds against or to cure any defects in Owner's title to the
          Premises. Owner agrees to cooperate with Vista if Vista undertakes any
          such action. Vista may credit against Vista's payment obligations
          under this Agreement and against the production payment provided for
          in the Mining Deed and recover from Owner any payments otherwise due
          or paid to Owner the reasonable costs and expenses, including
          attorney's fees, which Vista incurs in any such action. Owner may take
          curative steps, at its own expense, in lieu of Vista taking such
          curative action.

     (c)  Owner, to the best of its knowledge and belief, and except for
          existing drill roads and drill sites on the Premises, is not aware of
          any reclamation obligations from any past mineral exploration or
          development activities on or with respect to the Premises that remain
          unfulfilled with any local, state or federal agencies having
          jurisdiction over such activities and is not aware of any
          environmental condition or contamination on or connected with the
          Premises of any nature, including, but not limited to, contamination
          by any hazardous substances ("Hazardous Substances") as defined in the
          Comprehensive Environmental Response, Compensation and Liability Act,
          as amended, and as defined in the Resource Conservation Recovery Act
          and in any other applicable laws and regulations.

          Except for existing drill roads and drill sites on the Premises, the
          liability for which Vista hereby agrees to assume, Owner hereby
          indemnifies, defends, and holds Vista harmless from and against any
          and all claims, liabilities, losses, damages, costs and expenses,
          including but not limited to civil and criminal fines, penalties and
          interest, Superfund liability, clean-up costs, and reasonable
          attorney, environmental consultant, engineering, and expert fees,
          (collectively "Claims") arising out of or in connection with any
          reclamation obligation or Hazardous Substances or other environmental
          condition or contamination which exists on the Premises as of the
          effective date of this Agreement, or which is due to any act or
          omission of Owner and/or any prior occupants of the Premises.

     (d)  The unpatented mining claims included in the Premises have been
          properly located, and that for each assessment year either payment of
          annual maintenance fees or rentals have been paid or assessment work
          has been performed to properly maintain the unpatented mining claims
          in accordance with applicable state and federal laws and regulations.



                                       4
<PAGE>


     (e)  The location notices or location certificates for the unpatented
          mining claims included in the Premises have been properly filed in the
          proper office of the Bureau of Land Management in accordance with
          applicable Federal laws and regulations; and

     (f)  Evidence of assessment work, payment of maintenance fees or rentals or
          notices of intention to hold have been properly recorded in the proper
          county, or recording district office and filed in the proper office of
          the Bureau of Land Management in accordance with applicable Federal
          laws and regulations for each assessment year to and including the
          assessment year ending September 1, 2004.

     (g)  Before the execution of this Agreement, Owner has made available to
          Vista all drill core and/or drill cuttings and copies of all
          geological, geophysical, and engineering data and maps, logs of drill
          holes, results of assaying and sampling, and disclosed all additional
          data and information that Owner has knowledge of which may impact
          Vista's rights and obligations under this Agreement.

     (h)  Owner's representations and warranties in Section 5.1, subsections
          (a), (c), (d), (e) (f) and (g) shall survive Vista's exercise and
          Closing of the Purchase Option.

5.2  TITLE. Upon request by Vista, Owner shall provide Vista with recording data
     with respect to location notices and certificates, affidavits of annual
     labor, deeds, easements, or other documents which bear upon Owner's title
     to the Premises, and shall provide Vista with copies of all such documents
     and all title reports and abstracts in Owner's possession or control. Owner
     shall, upon Vista's request, record any such document in Owner's possession
     or control which has not been recorded.

5.3  LESSER INTEREST. Without impairment of the covenants and warranties of
     title contained in this Agreement, if Owner owns less than the entire
     undivided estate in the Premises, all Agreement payments and the Purchase
     Price shall be proportionately reduced and all payments due under this
     Agreement shall be payable to Owner only in the proportion that Owner's
     actual ownership interest in the Premises bears to the whole and undivided
     estate.

5.4  INSPECTION.

     (a)  Owner and its agents, employees, or personal representatives, duly
          authorized in writing, may inspect the activities of Vista on the
          Premises during normal business hours, provided, however, that (i)
          such inspection shall be made upon no less than twenty-four (24) hours
          prior notice given to Vista, and (ii) such inspection shall be subject
          to the safety requirements of Vista.

     (b)  Owner, in the exercise of this right, shall hold Vista harmless from
          all claims for damages arising out of any death, personal injury, or
          property damage sustained by Owner, its agents, employees, or personal
          representatives while in or upon the Premises, unless such death or
          injury arises as a direct result of the negligence or willful
          misconduct of Vista.


                                       5
<PAGE>


6.0  VISTA'S COVENANTS AND OBLIGATIONS.

6.1  EXPLORATION ACTIVITIES.

     (a)  Vista shall conduct all exploration and related activities on the
          Premises in a good and workmanlike manner and in accordance with
          accepted industry practices. All decisions with respect to the
          exploration of the Premises shall be made by Vista in its sole
          discretion.

     (b)  Vista shall comply with all valid state, federal, state and local laws
          and regulations governing its activities on the Premises. If this
          Agreement is inconsistent with or contrary to any law or regulation,
          the law or regulation shall control and this Agreement shall be deemed
          to be modified accordingly.

     (c)  Except as provided for in Section 5.4 (INSPECTION), Vista shall hold
          Owner harmless for all claims, loss, liability, liens or expense of
          any kind arising from or related to its activities on the Premises,
          excepting therefrom such claims or liability caused by the negligence
          or willful misconduct of Owner, its agents or employees. Vista agrees
          to indemnify Owner against any such claims or liability, including all
          costs and reasonable attorney's fees incurred by Owner in defending
          against such claim or liability.

6.2  INSURANCE. Vista shall carry at all times during the term of this
     Agreement, workmen's compensation and other insurance required by state
     laws and mining regulations.

6.3  REPORTS AND INFORMATION. During the term of this Agreement, Vista shall
     provide to Owner, annually, copies of drill-hole location maps,
     non-interpretive core analysis, drill hole logs, assay results and other
     factual reports from Vista's work on the Premises during the preceding
     year. Vista makes no representation or warranty as to the accuracy or
     completeness of any such data or information, and shall not be liable on
     account of any use by Owner or any other person of any such data or
     information. Vista shall not be responsible for the loss or destruction of
     any drill core. If Vista terminates this Agreement without exercising its
     Purchase Option, Vista shall provide Owner with all of the information
     previously obtained by Vista from Owner and with the above-listed data or
     information pertaining to the Premises that was generated by Vista, and not
     already provided to Owner, within thirty (30) days after termination.

6.4  CONFIDENTIALITY. Owner agrees to maintain all data, drill logs, assays,
     samples, reports, records, and other information and data relating to the
     Premises or Vista's operation on the Premises in strict confidence,
     including, without limitation, information obtained by the Owner through
     exercise of its inspection rights under Section 5.4 above during the term
     of this Agreement and thereafter if Vista exercises the Purchase Option
     pursuant to Section 4.2. Owner shall not disclose any such information to
     any person without the prior written consent of Vista. Information and data
     developed by Vista during the term of this Agreement is the property of
     Vista and, except as specifically provided in this Agreement, shall not be
     available to the Owner. Vista shall be entitled to injunctive relief to
     enforce its rights under this Section 6.4.



                                       6
<PAGE>


6.5  RECLAMATION. Vista shall comply with all local, state and federal laws and
     regulations relating to land reclamation. Should Vista terminate this
     Agreement before exercising its Option to Purchase, Vista agrees to reclaim
     surface disturbances resulting from its exploration activities on the
     Premises to conditions that are reasonably comparable to the conditions
     existing on the effective date of this Agreement and in accordance with all
     applicable local, state and federal laws and regulations.

     Vista shall be permitted to store, handle and dispose of substances on the
     Premises which may be regulated or defined as hazardous substances
     ("Hazardous Substances") as defined in the Comprehensive Environmental
     Response, Compensation and Liability Act, as amended, and as defined in the
     Resource Conservation Recovery Act and in any other applicable laws and
     regulations as long as Vista does so in compliance with the applicable laws
     and regulations. Vista represents and warrants that Vista shall at all
     times during the term of this Agreement be in compliance with all such laws
     and regulations and shall indemnify, defend and hold Owner harmless from
     and against any and all claims, liabilities, losses, damages, costs and
     expenses, including but not limited to civil and criminal fines, penalties
     and interest, Superfund liability, clean-up costs, and reasonable attorney,
     environmental consultant, engineering, and expert fees, arising out of or
     in connection with any Hazardous Substances or other environmental
     condition or contamination caused by Vista in violation of this Section.
     This Section 6.5 shall survive the termination of this Agreement.

6.6  MAINTENANCE FEES AND ASSESSMENT WORK.

     (a)  If Vista continues this Agreement beyond July 1, 2004, Vista shall pay
          any maintenance fee, rental, holding fee or other payment required
          under the federal mining laws to maintain the unpatented lode mining
          claims in the Premises. If any such law permits the performance of
          assessment work or annual labor in lieu of making all or a portion of
          any such payment, Vista shall determine whether to make such payment,
          perform such work or labor, or both.

     (b)  For each assessment year during the term of this Agreement in which
          Vista pays a maintenance fee, rental, holding fee or other payment, or
          performs annual labor or assessment work, it shall prepare and record
          in the County office where the location notices or location
          certificates are recorded and in the proper office of the Bureau of
          Land Management, an affidavit of payment of maintenance fees, rentals,
          holding fees or assessment work or other document complying with the
          requirements of state law and the Federal Land Policy and Management
          Act of 1976 and the regulations implementing and supplementing the
          Act.

     (c)  Vista shall have the benefit of all laws now existing or subsequently
          enacted which relate to such work or fees, including any laws
          extending the time within which to perform such work or to pay such
          fees, suspending such requirements, or exempting the unpatented mining
          claims in the Premises from such requirements. Vista shall be relieved
          of its obligation to perform such work or make such payments for any
          period in which such work or such payments are not required or are
          suspended under the federal mining laws.



                                       7
<PAGE>



6.7  AMENDMENTS. RELOCATIONS. AND PATENTS. During the term of this Agreement,
     Vista shall have the right, but not the obligation, to amend or relocate,
     in the name of Owner, any or all of the unpatented mining claims included
     in the Premises, to locate mill sites on ground theretofore covered by
     mining claims and vice versa, and to locate any fractions resulting from
     the location, amendment, or relocation of mining claims or mill sites. At
     the request of Vista, Owner shall apply for a patent for any or all of the
     unpatented mining claims. All expenses authorized by Vista in connection
     with locating, amending, or relocating mining claims or mill sites, or
     prosecuting patent proceedings shall be borne by Vista. The rights of Vista
     under this Agreement shall extend to all such locations, amended locations,
     relocations, and patented mining claims and mill sites.

7.0  TERMINATION. SURRENDER. AND DEFAULT.

7.1  DEFAULT. Should Vista fail to comply with any of the provisions of the
     Agreement, and should Vista not initiate and diligently pursue steps to
     correct the default within thirty (30) days after written notice has been
     given to it by Owner specifying with particularity the nature of the
     default, then upon the expiration of the thirty (30) day period, all rights
     of Vista under this Agreement, except as provided hereunder and in Section
     7.4 (REMOVAL OF PROPERTY), shall terminate, and all liabilities and
     obligations of Vista, except those liabilities existing on the date of
     termination, shall terminate.

     Should Vista, by notice given to Owner, dispute the existence of a default,
     then this Agreement shall not terminate hereunder unless Vista does not
     initiate and diligently pursue steps to correct the default within thirty
     (30) days after the default has been determined by a final decision of
     arbitrators or a court of competent jurisdiction.

7.2  TERMINATION. Vista may, at any time, terminate this Agreement as to all or
     any portion of the Premises by delivering to Owner or by filing for record
     in the appropriate office, with a copy to Owner, a good and sufficient
     Surrender or Partial Surrender of this Agreement. Upon mailing the
     Surrender or Partial Surrender to Owner or the appropriate County recording
     office, all rights of Vista under this Agreement with respect to the
     Premises, or portion of the Premises surrendered, except as provided in
     Section 7.4 (REMOVAL OF PROPERTY), shall terminate and all liabilities and
     obligations of Vista with respect to the Premises, or portion of the
     Premises surrendered, shall terminate on the date specified in the notice
     (except liabilities existing on the date of termination). Upon such
     termination by Vista, Vista shall also execute and deliver a Quitclaim Deed
     to Owner conveying the mining claims covered by this Agreement.

7.3  RIGHTS NOT TO BE SUSPENDED. Any dispute between the parties or resolution
     thereof relating to this Agreement shall not interfere with nor affect any
     right Vista may have under this Agreement.

7.4  REMOVAL OF PROPERTY. For a period of six (6) months following the
     termination of this Agreement, Vista shall have the right to remove from
     the Premises all structures, machinery, equipment, personal property,
     fixtures, and improvements owned by Vista or erected or placed on the
     Premises by Vista. Vista may keep one or more watchmen on the Premises
     during the six-month period.



                                       8
<PAGE>


8.0  RIGHT OF FIRST OFFER. If Owner desires to transfer all or any part of its
     interest in this Agreement or in the Premises to any third party, Vista
     shall have the right of first offer to acquire such interest as provided
     for in this Section 8.0.

     (a)  If Owner intends to transfer all or any part of its interest in this
          Agreement or in the Premises, Owner shall promptly notify Vista of its
          intentions. The notice shall state the price and all other pertinent
          terms and conditions of the intended transfer, which shall be for a
          monetary consideration only. Vista shall have sixty (60) days from the
          date such notice is delivered to notify Owner whether it elects to
          acquire the offered interest at the same price and on the same terms
          and conditions as set forth in the notice. If Vista does so elect, the
          transfer shall be consummated promptly after notice of such election
          is delivered to the Owner.

     (b)  If Vista fails to so elect within the period provided for in Section
          8.0(a), Owner shall have one hundred eighty (180) days following the
          expiration of such period to consummate the transfer to a third party
          at a price and on terms no less favorable to the Owner than those set
          forth in the notice required in Section 8.0(a) above. If Owner
          consummates the transfer to a third party, Owner will promptly notify
          Vista in writing of the transfer and will provide Vista with
          documentation of the terms of the transfer.

     (c)  If Owner fails to consummate the transfer to a third party within the
          period set forth in Section 8.0(b), Vista' right of first offer shall
          be deemed to be revived. Any subsequent proposal to transfer such
          interest shall be conducted in accordance with all of the procedures
          set forth in this Section 8.0. This right of first offer shall be
          binding upon any successors or assigns of Owner and upon any
          subsequent transfers by Owner or Owner's successors or assigns.

9.0  ASSIGNMENT/MULTIPLE PARTIES.

     (a)  Vista and Owner may assign all or any portion of their rights under
          this Agreement, subject to the provisions set forth below.

     (b)  Owner's right to assign any interest under this Agreement shall be
          subject to Vista's right of first offer as set forth in Section 8.0.

     (c)  No change or division of the ownership of the Premises or the payments
          provided for herein, however accomplished, shall enlarge the
          obligations nor diminish the rights of Vista. Owner covenants that any
          change in ownership shall be accomplished in such a manner that Vista
          shall be required to make payments and to give notices to but one
          person, firm, or corporation. No change or division in ownership shall
          be binding on Vista until thirty (30) days after Owner has delivered
          Vista a certified copy of the recorded instrument evidencing the
          change or division.

     (d)  Should Owner's interest in the Premises or payments now or hereafter
          be owned by more than one party, Vista may withhold payments until all
          such owners have designated a single party to act for all of them
          hereunder in all respects.



                                       9
<PAGE>


10.0 GENERAL PROVISIONS.

10.1 MEMORANDUM. Vista and Owner agree to enter into a Memorandum of this
     Agreement for the sole purpose of giving notice of the existence of this
     Agreement and of Vista's rights of access and its permitted activities on
     the Premises hereunder. Vista may record the Memorandum or this Agreement,
     or both, as it may elect.

10.2 ADDITIONAL DOCUMENTS. Owner shall provide Vista with such additional title
     documents as may be necessary to carry out the purposes of this Agreement.
     If conditions change by reason of conveyances, assignments, or other
     matters relating to the title or description of the Premises, Owner and
     Vista shall execute amendments to this Agreement and the Memorandum, and
     any other documents which may be necessary or convenient to reflect the
     changed conditions.

10.3 NOTICES. Any payment or notice required or desired to be given under this
     Agreement shall be effective when personally served upon the party to be
     given such payment or notice at the address designated below when deposited
     in the United States mail, certified return requested, or registered with
     postage thereon fully paid, when deposited with an express courier, or
     transmitted by telecopier, telex, or other electronic means of written
     communication. Until notified otherwise in writing, the addresses for such
     notices shall be as follows:

            If to Owner:            Hal Hewitt
                                    Monex Exploration
                                    5195 Rio Pinar
                                    Reno, Nevada 89509
                                    Fax: ____________


            If to Vista:            Attention:  President
                                    Vista Nevada Corp.
                                    7961 Shaffer Parkway, Suite 5
                                    Littleton, CO 80127
                                    Fax: 720-981-1186

     No change in address shall be binding on the other party until thirty (30)
     days after notice is communicated in the above manner. Routine or regular
     periodical reports and statements hereunder may be sent by regular mail so
     addressed.

10.4 SEVERABILITY. Should any court or administrative body of competent
     jurisdiction determine that any part, term, or provision of this Agreement
     is unenforceable, illegal, or in conflict with any state, federal, or local
     law, then, such part, term, or provision shall be considered severable from
     the rest of the Agreement, and the remaining provisions of the Agreement
     shall not be thereby affected, and this Agreement shall be construed and
     enforced as if the Agreement did not contain such part, term, or provision.



                                       10
<PAGE>


10.5 SOLE AGREEMENT. This Agreement, together with its exhibits, contains the
     entire agreement by and between Owner and Vista and no oral agreement,
     promise, statement, or representation which is not contained herein shall
     be binding on the parties. This Agreement shall not be modified or amended
     except by a writing signed by the parties hereto.

10.6 BINDING EFFECT. CONSTRUCTION. AND ENFORCEMENT. All covenants, conditions,
     and terms of this Agreement shall be of benefit to and run with the
     Premises and shall bind and inure to the benefit of the parties hereto,
     their respective successors and assigns. This Agreement shall be construed
     and enforced in accordance with the laws of the State of Nevada.

10.7 TITLES. The titles to the respective sections hereof shall not be deemed a
     part of this Agreement but shall be regarded as having been used for
     convenience only.

10.8 RELATIONSHIP. Nothing contained in this Agreement shall be construed or
     deemed to create or constitute a joint venture, mining partnership,
     commercial partnership, or other partnership in relation.

10.9 COUNTERPARTS. This Agreement may be executed in any number of counterparts,
     each of which shall be deemed to be an original. If any person named as
     Owner does not execute this Agreement, it shall nevertheless be binding
     upon those persons executing it.


IN WITNESS WHEREOF, the parties have executed this Agreement as of the date
first above written.


OWNER:                                   VISTA:
Monex Exploration, a partnership         Vista Nevada Corp, a Nevada corporation



By:_______________________________       By:_________________________________
   E. Chapel, individually and as
   a partner of Monex Exploration

                                         Title:______________________________


By:_______________________________
   Deborah H. Shields, individually
   and as a partner of Monex Exploration





                                       11
<PAGE>




STATE OF NEVADA      )
                     ss.
COUNTY OF WASHOE     )

This Option to Purchase Agreement was acknowledged before me this _____ day of
September, 2003, by E. Chapel , individually and as a Partner of Monex
Exploration.


                                            ------------------------------------
                                            Notary Public

STATE OF NEVADA      )
                     ss.
COUNTY OF WASHOE     )

This Option to Purchase Agreement was acknowledged before me on this _____ day
of September, 2003, by Deborah H. Shields, individually and as a Partner Monex
Exploration.

                                            ------------------------------------
                                            Notary Public

STATE OF COLORADO    )
                     ss.
COUNTY OF JEFFERSON  )

This Option to Purchase Agreement was acknowledged before me on this _____ day
of September, 2003, by __________________________ as __________________________
of Vista Nevada Corp.

                                            ------------------------------------
                                            Notary Public




<PAGE>


                                    EXHIBIT A
             OPTION TO PURCHASE AGREEMENT BETWEEN MONEX EXPLORATION
                              AND VISTA GOLD CORP.
                             DESCRIPTION OF PREMISES

The following described unpatented lode mining claims are located in Sections
__________________, Township ___ North, Range ___ East, Mount Diablo Base and
Meridian, in Pershing County, Nevada:


             CLAIM NAME                          BLM NMC NOS.
             ----------                          ------------