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                                                                     EXHIBIT 4.3



                                 PROMISSORY NOTE

U.S.$7,500,000.00                                                  June 30, 2001


                  FOR VALUE RECEIVED, CCBM, Inc. (together with its successors
and assigns, the "Maker") by this promissory note (this "Note") hereby
unconditionally promises to pay to the order of ROCKY MOUNTAIN GAS, INC.
(together with its successors and assigns, "Payee"), the principal sum of Seven
Million Five Hundred Thousand and No/One-Hundredths Dollars (U.S.$7,500,000.00)
in installments as hereinafter provided and to pay interest on the principal
balance hereof from time to time outstanding, as hereinafter provided, at the
rate of 8% per annum.

                  The terms used in this Note shall have the following meanings:

                  (a) The term "Business Day" shall mean any day upon which
commercial banks are open for the transaction of business in Houston.

                  (b) The term "Mortgaged Properties" shall have the meaning
given to such term in the Mortgage and Financing Statement dated June 9, 2001,
as the same may be modified or amended from time to time.

                  (c) The term "Loan Documents" shall collectively mean this
Note, the Mortgage and Financing Statement and all other documents and
instruments now or hereafter executed and delivered in connection therewith or
otherwise pertaining to this Note, as the same may be modified or amended from
time to time.

                  The principal hereof shall be paid in forty-one (41)
installments, of $125,000 each, payable on the last Business Day of each month,
commencing July 31, 2001 (each a "Payment Date"). On December 31, 2004, the
Maker shall repay in full the outstanding principal, together with accrued but
unpaid interest.

                  Interest on this Note is payable on each Payment Date,
beginning on July 31, 2001. Interest will be calculated on the basis of the
actual number of days elapsed (including the first day, but excluding the last
day) over a year of 365 days.

                  This Note may be prepaid, in whole or in part, at any time
without penalty or premium.

                  The Maker hereby waives demand, diligence, presentment,
protest and notice of every kind, and warrants to the holder that all action and
approvals required for the execution and delivery hereof as a legal, valid and
binding obligation of the undersigned, enforceable in accordance with the terms
hereof, have been duly taken and obtained.

                  This Note is secured by certain leasehold interests and
property rights which are identified in the Mortgage and Financing Statement,
together with all of Maker's right, title and interest therein or otherwise
described as set forth therein.
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                  Payee shall not enforce the liability and obligation of Maker
under this Note and the other Loan Documents by any action or proceeding wherein
a money judgment shall be sought against Maker, except that Payee may bring a
foreclosure action or any other appropriate action or proceeding to enable Payee
to enforce and realize upon its interest in the Mortgaged Properties; provided
any judgment in any such action or proceeding shall be enforceable against Maker
only to the extent of Maker's interest in the Mortgaged Properties, and Payee,
by accepting this Note, agrees that it shall not sue for, seek or demand any
deficiency judgment against Maker in any such action or proceeding under or by
reason of or under or in connection with this Note or any other Loan Document.

                  In the event Maker defaults on this Note and Payee is required
to bring legal action against Maker on this Note, Maker shall be entitled to
recover all attorney's fees, costs and expenses incurred as a result of such
default.

                  THIS NOTE SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE
WITH, THE LAW OF THE STATE OF WYOMING, U.S.A.

                                   CCBM, Inc.


                                   By:
                                        ----------------------------------------
                                                     (Signature)

                                   Name:
                                          --------------------------------------
                                                       (Print)

                                   Title:
                                           -------------------------------------

ACCEPTED:

ROCKY MOUNTAIN GAS, INC.


By:
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Name:
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Title:
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