<PAGE>
                                                                  Exhibit 10.2.6

                           AMENDMENT NO. 6 AND WAIVER

         AMENDMENT NO. 6 AND WAIVER (this "Amendment") dated as of June 14,
2002, among CR BRIGGS CORPORATION (the "Company"), a corporation organized under
the laws of the State of Colorado, the Lenders named on the signature pages
hereof, and BNP PARIBAS, as successor-in-interest to Banque Paribas, New York
Branch, in its capacity as agent for the Lenders (the "Agent").

                                   WITNESSETH:

         WHEREAS, the Company, the Lenders and the Agent have entered into the
Loan Agreement dated as of December 6, 1995, and amended as of April 8, 1998,
August 19, 1998, July 8, 1999, March 26, 2001 and March 25, 2002 (as amended,
modified and supplemented from time to time, the "Loan Agreement"), providing
for certain Loans to be made to the Company by the Lenders to finance the
acquisition and construction of the Project;

         WHEREAS, the Company has requested that the Loan Agreement be further
amended and that certain matters be waived by the Lenders, subject and pursuant
to the terms and conditions of this Amendment;

         NOW, THEREFORE, the Company, the Lenders and the Agent wish to amend
the Loan Agreement in certain respects, and accordingly, the parties hereto
agree as follows:

         Section 1. Definitions. Terms used but not defined herein shall have
the respective meanings ascribed to such terms in the Loan Agreement.

         Section 2. Conditions Precedent. The agreements set forth in Sections 3
and 4 of this Amendment shall be subject to the occurrence of the following: (i)
the Lenders receipt of an Officer's Certificate that no Event of Default, which
is not otherwise being waived by the terms hereof, under the Loan Agreement
shall have occurred and be continuing; and (ii) Closing occurring pursuant to
the Agreement described in Section 3 below.

         Section 3. Waiver. Subject to the occurrence of the conditions
described in Section 2 above and the Company's and Guarantor's compliance with
the provisions of Section 4 below, the Lenders hereby waive: (i) the default
caused by Company's failure to make the Loan payment due in May, 2002; and (ii)
the requirements and obligations of the Company under Section 8.07 of the Loan
Agreement with respect to the sale by the Company of the crusher at the Project
(the "Crusher") pursuant to the terms and conditions set forth in that certain
Purchase Agreement, dated effective May 14, 2002 ("Agreement"), between
Guarantor and Corner Bay Silver Inc. ("Corner Bay"), a copy of which Agreement
is attached as Exhibit A hereto.

                                       1
<PAGE>

         Section 4. Amendments. The Loan Agreement is amended as follows:

         (a) Add the following provision after the last sentence of Section 8.07
of the Loan Agreement:

                  "Notwithstanding the foregoing provisions of the prior
         sentence of this Section 8.07, the proceeds from the sale of the
         Crusher pursuant to the Agreement shall, within five (5) days of
         receipt by Borrower or Guarantor, be applied in the following
         priorities: (i) U.S. $600,000 in payments necessary to remove
         mechanics' and materialmen's liens, potential defaults and obligations
         to vendors; (ii) U.S. $502,358.80, as payment necessary to pay off the
         purchase money security interest lien on the Crusher, currently held by
         John Deere Corporation; (iii) U.S. $950,000 to repayment of the Loans,
         50% of which (i.e., U.S. $475,000) shall be applied to Loan payments
         due starting in May, 2002, and 50% of which (i.e., U.S. $475,000) shall
         be applied to Loan payments due, in reverse order of maturity, starting
         with the June, 2003 payment, and (iv) 75% of amounts in excess of the
         amounts in (i), (ii) and (iii) above will be applied to Loan payments
         in reverse order of maturity, starting in April, 2003, and 25% of which
         shall be applied to Loan payments due in order of maturity, starting in
         August, 2002."

         (b) The text of Section 8.29, which was added to the Loan Agreement by
         Amendment No. 5, dated March 25, 2002, is deleted in its entirety and
         replaced with the following provisions: "To the extent that Borrower
         reduces total trade accounts payable below $2,250,000, the Lenders will
         receive payments, which shall be applied to the Principal balance due,
         equal to all such reductions."

                  Section 5. Guarantor Covenant. Guarantor, by its execution of
this Amendment, hereby covenants that: (i) if and to the extent it receives any
payments or proceeds pursuant to the Agreement, it shall cause these proceeds
and payments to be paid and applied as described in Section 4 above; and (ii)
Guarantor's guarantee obligations under the Guarantee Agreement shall remain in
full force and effect.

                  Section 6. Agent and Lender Covenant. Agent and Lender hereby
covenant to execute such releases of Security Documents with respect to the
Crusher as may be reasonably requested by the Company, in order to pursue the
sale of the Crusher.

                  Section 7. Documents Otherwise Unchanged. Except as herein
provided, the Loan Agreement shall remain unchanged and in full force and
effect, and each reference to the Loan Agreement shall be a reference to the
Loan Agreement as amended hereby and as the same may be further amended,
supplemented and otherwise modified and in effect from time to time.

                  Section 8. Counterparts. This Amendment may be executed in any
number of counterparts, each of which shall be identical and all of which, when
taken together, shall constitute one and the same instrument, and any of the
parties hereto may execute this Amendment by signing any such counterpart.

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<PAGE>

                  Section 9. Binding Effect. This Amendment shall be binding
upon and inure to the benefit of the parties hereto and their respective
successors and assigns.

                  Section 10. Governing Law. This Amendment shall be governed
by, and construed in accordance with, the laws of the State of New York.

         IN WITNESS WHEREOF, the parties hereto have caused this Waiver to be
duly executed as of the day and year first above written.

                                           "BORROWER"

                                           CR BRIGGS CORPORATION

                                           By:      /s/Gary C. Huber
                                                  ---------------------------
                                           Name:    Gary C. Huber
                                                  ---------------------------
                                           Title:   Vice President
                                                  ---------------------------

                                           "GUARANTOR"

                                           CANYON RESOURCES CORPORATION

                                           By:      /s/ Gary C. Huber
                                                  ---------------------------
                                           Name:    Gary C. Huber
                                                  ---------------------------
                                           Title:   Vice President
                                                  ---------------------------

                                           "AGENT"

                                           BNP PARIBAS, as agent for the Lenders

                                           By:      /s/ Sean Finnegan
                                                  ---------------------------
                                           Name:      Sean Finnegan
                                                  ---------------------------
                                           Title:   Vice President
                                                  ---------------------------

                                           "LENDERS"

                                           BNP PARIBAS

                                           By:       /s/ Barry Liu
                                                  ---------------------------
                                           Name:    Barry Liu
                                                  ---------------------------
                                           Title:   Vice President
                                                  ---------------------------

                                           By:      /s/ Sean Finnegan
                                                  ---------------------------
                                           Name:    Sean Finnegan
                                                  ---------------------------
                                           Title:   Vice President
                                                  ---------------------------

                                       3
<PAGE>

                                           BAYERISCHE HYPO-UND
                                           VEREINSBANK AG, NEW YORK
                                           BRANCH


                                           By:      /s/ Andrew G. Mathews
                                                  ---------------------------
                                           Name:    Andrew G. Mathews
                                                  ---------------------------
                                           Title:   Managing Director
                                                  ---------------------------


                                           By:      /s/ Carmen De Paula
                                                  ---------------------------
                                           Name:    Carmen De Paula
                                                  ---------------------------
                                           Title:   Associate Director
                                                  ---------------------------

                                          NM ROTHSCHILD & SONS LIMITED

                                           By:      /s/ C. Coleman
                                                  ---------------------------
                                           Name:    C. Coleman
                                                  ---------------------------
                                           Title:   Director
                                                  ---------------------------


                                           By:      /s/ N. A. Wood
                                                  ---------------------------
                                           Name:    Nicholas A. Wood
                                                  ---------------------------
                                           Title:   Assistant Director
                                                  ---------------------------

                                      4
<PAGE>


                                    EXHIBIT A

                               PURCHASE AGREEMENT

Canyon Resources Corporation of 14142 Denver West Parkway, Suite 250, Golden,
Colorado 80401

Dear Sirs:

RE:      BRIGGS MINE CRUSHING PLANT AND ANCILLARY ITEMS LOCATED IN CALIFORNIA

This letter will set out the general terms and conditions of the proposed
purchase of the Briggs Mine Crushing Plant and Ancillary Items (the "PLANT") of
Canyon Resources Corporation (the "CORPORATION") by Corner Bay Silver Inc. or
such other corporation as may be chosen by Corner Bay Silver Inc. (the
"PURCHASER").

It is the intent of this letter that it set out with sufficient particularity
the details of the transaction contemplated by the parties so that the parties
may establish the general terms of the formal, comprehensive asset purchase
agreement (the "AGREEMENT") to be executed by them and which will be prepared
for the Closing (the "CLOSING"), which will take place within 30 days of the
Corporation's signature of this letter, as more fully set forth at paragraph
4(a) hereof. This letter shall be legally binding and shall be effective as of
its signature by the Corporation, and shall constitute the sole contract between
the Corporation and Purchaser if the final Agreement is not executed within 30
days of Corporation's signature of this letter.

1.       ASSETS

The Purchaser will purchase the Plant, which is 100% owned or leased by the
Corporation and more particularly described in Schedule A attached to this
letter. All such assets comprising the Plant will be purchased free and clear of
any encumbrances and will be purchased upon the following terms and conditions:

         (a)      The Purchaser will purchase the Plant that will include
                  machinery, equipment and ancillary items as set out in
                  Schedule A. Such assets as set out in Schedule A are intended
                  to be removed from the Corporation's property in the State of
                  California, USA and transported at Purchaser's cost to the
                  Purchaser's property in Sonora, Mexico by common carrier.

         (b)      The Corporation will provide all documentation in its
                  possession related to the design, installation, maintenance,
                  and operation of items listed in Schedule A, including, but
                  not limited to, manufacturer's operating and maintenance
                  manuals, specifications and drawings related to the original
                  and subsequent installation of equipment, Corporation's
                  operating and maintenance history, including preventive
                  maintenance procedures and records and correspondence relating
                  to purchase, maintenance and operation of equipment. All
                  warranties and




                                       1
<PAGE>

                  maintenance records with respect to machinery, equipment and
                  ancillary items are to be made available as soon as practical
                  and transferred to the Purchaser, in all cases before Closing.

         (c)      The Corporation will give to the Purchaser and its
                  representatives such access to the property (the "PREMISES")
                  where the Plant is located, and such other authorization as
                  may be necessary, to enable the Purchaser and its
                  representatives to conduct reviews of the Plant and to
                  complete activities related to the dismantling and movement of
                  the equipment off-site. The Purchaser will endeavour to remove
                  all equipment from the Premises within 180 days from the date
                  this letter is signed by the Corporation. Purchaser will
                  ensure that the immediate Plant area is left free of all
                  equipment described in Schedule A and that only concrete
                  foundations are remaining upon completion.

         (d)      After Closing, the Corporation will provide as part of the
                  Agreement, without additional cost, up to 500 hours of use of
                  the Corporation's 40-ton crane for use in the dismantling and
                  loading of trucks to transport equipment off-site. The crane
                  will normally be available to the Purchaser during daylight
                  hours during a 12-week period after Closing when the equipment
                  is disassembled and transported. Purchaser will provide fuel,
                  lubricants, and operator and make the crane available for
                  preventive and corrective maintenance, as required. The
                  Corporation will also provide, during the 12-week dismantling
                  and shipping period, electrical power and water as required
                  to: (i) test operate machinery and motors, (ii) make repairs
                  as needed, and (iii) clean and prepare equipment for shipment.

         (e)      No action taken by the Purchaser or its representatives
                  hereunder shall constitute a trespass. If, prior to the end of
                  the date fixed for Closing, the Purchaser elects for any
                  reason not to proceed with the purchase of the Plant, it may
                  terminate the Agreement by giving written notice to the
                  Corporation of its intention to so terminate, whereupon all of
                  the obligations otherwise imposed upon the Purchaser under the
                  Agreement shall be of no further force or effect, and
                  Corporation shall be entitled to retain the down payment of
                  US$250,000 paid by the Purchaser pursuant to paragraph 2(a).
                  If the Purchaser has not provided payment of shares pursuant
                  to paragraph 2(b) within 30 days of the date of acceptance of
                  this letter, then the Agreement will terminate with no further
                  obligations between the parties, unless the parties mutually
                  agree to extend the Closing date, and Corporation shall be
                  entitled to retain the down payment of US$250,000 paid by
                  Purchaser pursuant to paragraph 2(a).

         (f)      The Purchaser will not assume any liabilities of the
                  Corporation, other than as expressly provided herein. Without
                  limiting the generality of the foregoing, it is understood and
                  agreed that the following liabilities are not being assumed by
                  the Purchaser:

                  i)       sales commission payable with respect to the
                           transactions described herein,

                                       2
<PAGE>

                  ii)      insurance coverage of the Plant until the Purchaser
                           has taken possession and title at Closing, and

                  iii)     any and all environmental liabilities associated with
                           the Plant.


2.       PURCHASE PRICE

         (a)      Upon the Corporation's signature of this letter, the Purchaser
                  will pay to the Corporation a down payment of US$250,000 to
                  secure an exclusive 30-day purchase period for the Plant,
                  commencing at the date of the Corporation's signature of this
                  letter. This payment is refundable only if the Corporation's
                  Board of Directors fails to approve the sale of the Plant or
                  the Corporation otherwise fails to give effect to the
                  transaction contemplated herein.

         (b)      Upon Closing, 850,000 common shares of the Purchaser shall be
                  issued to the Corporation, subject to appropriate regulatory
                  approval. It is anticipated that a hold period will be imposed
                  on the shares. Notwithstanding such restrictions, the
                  Corporation shall be allowed to sell shares, provided that,
                  such sales are in compliance with applicable securities laws
                  and regulations.

         (c)      If the net price received by the Corporation from the sale of
                  all of the shares (i.e., net of commissions, discounts, taxes
                  and other fees for transfer or sale), plus the amount of cash
                  paid to the Corporation pursuant to paragraph 2(a), is less
                  than US$2,250,000, the Purchaser shall pay the difference to
                  Corporation by wire transfer in immediately available funds,
                  within 10 calendar days after being notified in writing by the
                  Corporation of the amount of that difference. The Corporation
                  shall accompany that notice with reasonable documentation that
                  evidences the amount of net price received by the Corporation.

3.       CONDUCT OF BUSINESS

From the date of its signature of this letter until the Closing, the Corporation
will maintain the Plant in the ordinary and usual course, properly insured, will
confer regularly with the Purchaser to report on the status of the Plant and
will not make any decisions likely to have a material effect on the Plant,
including Plant operation, without consulting with and obtaining the approval of
the Purchaser (such approval not to be unreasonably withheld).

4.       DATE OF THE AGREEMENT AND CLOSING

         (a)      The Closing will take place within 30 days of the date of the
                  Corporation's signature of this letter. If the signature of
                  this letter has not occurred by May 15, 2002, then the entire
                  offer to purchase shall be null and void. The Corporation
                  shall provide usual and normal representations and warranties
                  in respect of its sole and unencumbered ownership of the Plant
                  to allow the Purchaser to take free and clear title and
                  control of the Plant and remove the Plant from the
                  Corporation's

                                       3
<PAGE>
                  Premises. OTHERWISE, CORPORATION MAKES NO IMPLIED OR EXPRESS
                  WARRANTIES REGARDING THE CONDITION OF THE PLANT OR REGARDING
                  ITS FITNESS FOR ANY PARTICULAR PURPOSE, AND PURCHASER TAKES
                  THE PLANT "AS IS".

         (b)      Closing is subject to the approval by the Boards of Directors
                  of the Corporation and the Purchaser, as well as all required
                  regulatory approvals, within the 30-day period described in
                  Paragraph 4(a).


5.       CONFIDENTIALITY

The Purchaser and the Corporation will keep this letter and their mutual
interest in a proposed transaction (as well as all information obtained in
connection with their respective due diligence investigations), including any
negotiations between the Purchaser and the Corporation in respect thereof,
strictly confidential except as required by regulatory authorities. Upon
execution of this letter, the Corporation will cease any and all discussions,
whether direct or indirect, with persons other than the Purchaser, with respect
to the sale of the Plant and will enter into no other discussions with third
parties prior to either of the termination events set forth in paragraphs 1(e)
or 4(b).

6.       TERMINATION

This letter may be terminated and the transaction contemplated hereby may be
abandoned or terminated:

         (a)      at any time by the mutual agreement of the parties hereto,

         (b)      by the Purchaser, as set forth in paragraphs 1(e) and 4(b); or

         (c)      by the Corporation, as set forth in paragraph 4(b).


7.       GENERAL PROVISIONS

         (a)      Each party hereto represents and warrants that it is duly
                  authorized and has all necessary power and authority to
                  execute and deliver this letter and to perform its obligations
                  hereunder. It is expressly agreed and acknowledged that no
                  other agreement or meeting of the minds has been reached.
                  Accordingly, if for any reason whatsoever the purchase of the
                  Plant is not consummated, no party hereto shall be entitled to
                  any form of relief whatsoever, including, without limitation,
                  injunctive relief or damages.

         (b)      This letter may be executed in two or more counterparts, any
                  one of which need not contain the signature of more than one
                  party, but all such counterparts taken


                                       4
<PAGE>
                  together will constitute one and the same agreement and shall
                  be governed by the laws of the State of California.

         (c)      Each party hereto shall bear all expenses incurred by it in
                  connection with this letter, including, without limitation,
                  the charges of their respective legal counsel, accountants,
                  financial advisors and finders.


Please indicate your consent and agreement to the foregoing by signing both
copies of this Option to Purchase Agreement in the space provided below and
returning one fully executed copy (which return may be made by fax to (416)
368-7141).

                                        Yours very truly,

                                        Corner Bay Silver Inc.
                                        ("Purchaser")


                                        By:
                                           -------------------------------------
                                            Authorized Signing Officer



Agreed to and acknowledged this          day of May, 2002.


                                        Canyon Resources Corporation
                                        ("Corporation")


                                        By:

                                           -------------------------------------
                                            Authorized Signing Officer

                                       5