1
                                                                 Exhibit (a)(2)


                             LETTER OF TRANSMITTAL

                        TO TENDER SHARES OF COMMON STOCK
           (INCLUDING THE ASSOCIATED PREFERRED STOCK PURCHASE RIGHTS)

              PURSUANT TO THE OFFER TO PURCHASE DATED MAY 14, 2001

                                       OF

                         BARRETT RESOURCES CORPORATION
                                       TO

                          RESOURCES ACQUISITION CORP.,
                          A WHOLLY-OWNED SUBSIDIARY OF

                          THE WILLIAMS COMPANIES, INC.
- --------------------------------------------------------------------------------
     THE OFFER, PRORATION PERIOD AND WITHDRAWAL RIGHTS WILL EXPIRE AT 12:00
MIDNIGHT, EASTERN TIME, ON MONDAY, JUNE 11, 2001, UNLESS THE OFFER IS EXTENDED.
- --------------------------------------------------------------------------------

                        The Depositary for the Offer is:

                         EQUISERVE TRUST COMPANY, N.A.


                                                                
            By Mail:                     By Overnight Courier:                    By Hand:
     Attn: Corporate Actions            Attn: Corporate Actions            Attn: Corporate Actions
         P.O. Box 43025                   40 Campanelli Drive               Securities Transfer &
    Providence, RI 02940-3025             Braintree, MA 02184             Reporting Services, Inc.
                                                                                C/O EquiServe
                                                                        100 William Street, Galleria
                                                                             New York, NY 10038

                                             By Facsimile:
                                   (for Eligible Institutions only)
                                            (781) 575-4826
                                    Confirm Facsimile By Telephone:
                                            (781) 575-4816




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                                                DESCRIPTION OF SHARES TENDERED
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               NAME(S) AND ADDRESS(ES) OF REGISTERED HOLDER(S)                          SHARE CERTIFICATE(S) ENCLOSED
(PLEASE FILL IN, IF BLANK EXACTLY AS NAME(S) APPEAR(S) ON SHARE CERTIFICATE(S)  (ATTACH ADDITIONAL SIGNED LIST IF NECESSARY)
- ------------------------------------------------------------------------------------------------------------------------------
                                                                                                 
                                                                                        SHARE             NUMBER OF SHARES
                                                                               CERTIFICATE NUMBER(S)*        TENDERED**
                                                                               ----------------------------------------------

                                                                               ----------------------------------------------

                                                                               ----------------------------------------------

                                                                               ----------------------------------------------

                                                                               ----------------------------------------------

                                                                               ----------------------------------------------

                                                                               ----------------------------------------------
                                                                                    TOTAL SHARES
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 * Certificate numbers are not required if tender is made by book-entry
   transfer.

** If you desire to tender fewer than all Shares represented by a certificate
   listed above, please indicate in this column the number of Shares you wish to
   tender. Otherwise, all Shares represented by such certificate will be deemed
   to have been tendered. See Instruction 4.
   2

                               LOST CERTIFICATES

[ ]  I have lost my Certificates that represented ________ Shares and require
     assistance in obtaining replacement Certificates. I understand that I must
     contact the EquiServe, the Transfer Agent for Barrett Resources, to obtain
     instructions for replacing lost Certificates. Call EquiServe at
     1-800-736-3001. (See Instruction 9.)

      DELIVERY OF THIS LETTER OF TRANSMITTAL TO AN ADDRESS OTHER THAN AS SET
FORTH ABOVE, OR TRANSMISSION OF INSTRUCTIONS VIA FACSIMILE TO A NUMBER OTHER
THAN AS LISTED ABOVE DOES NOT CONSTITUTE A VALID DELIVERY. YOU MUST SIGN THIS
LETTER OF TRANSMITTAL WHERE INDICATED BELOW.

      THE INSTRUCTIONS ACCOMPANYING THIS LETTER OF TRANSMITTAL SHOULD BE READ
CAREFULLY BEFORE THIS LETTER OF TRANSMITTAL IS COMPLETED.

      This Letter of Transmittal is to be completed by stockholders of Barrett
Resources Corporation if certificates ("Share Certificates") representing shares
of common stock, par value $0.01 per share, (including the associated Rights (as
defined herein), the "Shares"), are to be forwarded herewith or, unless an
Agent's Message (as defined in the Offer to Purchase) is utilized, if delivery
of Shares is to be made by book-entry transfer to an account maintained by
EquiServe Trust Company, N.A. ("EquiServe" or the "Depositary") at The
Depositary Trust Company (the "Book-Entry Transfer Facility") pursuant to the
procedures set forth in Section 3 of the Offer to Purchase dated May 14, 2001
(the "Offer to Purchase"). DELIVERY OF DOCUMENTS TO THE BOOK-ENTRY TRANSFER
FACILITY IN ACCORDANCE WITH THE BOOK-ENTRY TRANSFER FACILITY'S PROCEDURES DOES
NOT CONSTITUTE DELIVERY TO THE DEPOSITARY.

      Stockholders whose Share Certificates are not immediately available or who
cannot deliver their Share Certificates and all other required documents to the
Depositary on or prior to the expiration date of the Offer or who are unable to
complete the procedure for book-entry transfer prior to the expiration date of
the Offer may nevertheless tender their Shares pursuant to the guaranteed
delivery procedures set forth in Section 3 of the Offer to Purchase. See
Instruction 2 below.

NOTE:  SIGNATURE(S) MUST BE PROVIDED BELOW. PLEASE READ THE INSTRUCTIONS SET
       FORTH IN THIS LETTER OF TRANSMITTAL CAREFULLY.

[ ]  CHECK HERE IF SHARES ARE BEING DELIVERED BY BOOK-ENTRY TRANSFER MADE TO AN
     ACCOUNT MAINTAINED BY THE DEPOSITARY WITH THE BOOK-ENTRY TRANSFER FACILITY
     AND COMPLETE THE FOLLOWING:
     Name of Tendering Institution:
    ----------------------------------------------------------------------------

     Provide Account Number and Transaction Code Number:

     Account Number:
    ----------------------------------------------------------------------------
     Transaction Code Number:
    ----------------------------------------------------------------------------

[ ] CHECK HERE IF CERTIFICATES FOR TENDERED SHARES ARE BEING DELIVERED PURSUANT
    TO A NOTICE OF GUARANTEED DELIVERY PREVIOUSLY SENT TO THE DEPOSITARY AND
    COMPLETE THE FOLLOWING. PLEASE ENCLOSE A PHOTOCOPY OF SUCH NOTICE OF
    GUARANTEED DELIVERY.
    Name(s) of Registered Holder(s):
    ----------------------------------------------------------------------------
    Window Ticket Number (if any):
    ----------------------------------------------------------------------------
    Date of Execution of Notice of Guaranteed Delivery:
    --------------------------------------------------------------
    Name of Institution which Guaranteed Delivery:
    -------------------------------------------------------------------

IF DELIVERED BY BOOK-ENTRY TRANSFER TO THE BOOK-ENTRY TRANSFER FACILITY, CHECK
BOX:  [ ]

Account Number:
- --------------------------------------------------------------------------------

Transaction Code Number:
- --------------------------------------------------------------------------------

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Ladies and Gentlemen:

      The undersigned hereby tenders to Resources Acquisition Corp.,
("Purchaser"), a Delaware corporation and a wholly-owned subsidiary of The
Williams Companies, Inc. ("Williams"), the above-described shares of common
stock, par value $0.01 per share (including the associated Rights (as defined
below), the "Shares"), of Barrett Resources Corporation, a Delaware corporation
("Barrett Resources"), pursuant to Purchaser's offer to purchase 16,730,502
Shares at $73.00 per Share, net to the seller in cash, without interest, upon
the terms and subject to the conditions set forth in the Offer to Purchase dated
May 14, 2001 (the "Offer to Purchase"), receipt of which is hereby acknowledged,
and in this Letter of Transmittal (which, as amended or supplemented from time
to time, together with the Offer to Purchase constitute the "Offer"). As used
herein, "Rights" means the preferred stock purchase rights associated with the
Shares and outstanding under the Rights Agreement (the "Rights Agreement") dated
as of August 5, 1997 by and between Barrett Resources and Fleet National Bank,
as successor to BankBoston, N.A., as Rights Agent, as amended. Unless the
context otherwise requires, all references to Shares shall be deemed to include
the associated Rights, and all references to the Rights shall be deemed to
include the benefits that may inure to holders of the Rights pursuant to the
Rights Agreement.

      Subject to, and effective upon, acceptance for payment of the Shares
tendered herewith, in accordance with the terms of the Offer, the undersigned
hereby sells, assigns and transfers to or upon the order of Purchaser all right,
title and interest in and to all the Shares that are being tendered hereby and
all dividends, non-cash distributions (including, without limitation,
distributions of additional Shares) and any rights declared, paid or distributed
in respect of such Shares on or after May 7, 2001 (collectively,
"Distributions") and irrevocably appoints EquiServe Trust Company, N.A. (the
"Depositary"), as the true and lawful agent and attorney-in-fact of the
undersigned with respect to such Shares and all Distributions, with full power
of substitution (such power of attorney being deemed to be an irrevocable power
coupled with an interest), to (i) deliver certificates representing Shares
("Share Certificates") and all Distributions, or transfer ownership of such
Shares and all Distributions on the account books maintained by the Book-Entry
Transfer Facility, together, in either case, with all accompanying evidences of
transfer and authenticity, to or upon the order of Purchaser; (ii) present such
Shares and all Distributions for transfer on the books of Barrett Resources; and
(iii) receive all benefits and otherwise exercise all rights of beneficial
ownership of such Shares and all Distributions, all in accordance with the terms
of the Offer.

      Barrett Resources has distributed one Right for each outstanding Share
pursuant to the Rights Agreement. The Rights are currently evidenced by and
trade with certificates evidencing the Shares. Barrett Resources has taken such
action so as to make the Rights Agreement inapplicable to Williams, Purchaser
and their respective affiliates and associates in connection with the
transactions contemplated by the Merger Agreement (as defined in the Offer to
Purchase).

      The undersigned hereby irrevocably appoints each of William G. von Glahn
and Jack D. McCarthy as agent, attorney-in-fact and proxy of the undersigned,
each with full power of substitution and resubstitution, to vote in such manner
as such attorney and proxy or his substitute shall, in his sole discretion, deem
proper and otherwise act (by written consent or otherwise) with respect to all
the Shares tendered hereby which have been accepted for payment by Purchaser
prior to the time of such vote or other action and all Shares and other
securities issued in Distributions in respect of such Shares, which the
undersigned is entitled to vote at any meeting of stockholders of Barrett
Resources (whether annual or special and whether or not an adjourned or
postponed meeting) or consent in lieu of any such meeting or otherwise. This
proxy and power of attorney is coupled with an interest in the Shares tendered
hereby, is irrevocable and is granted in consideration of, and is effective
upon, the acceptance for payment of such Shares by Purchaser in accordance with
the terms of the Offer. Such acceptance for payment shall revoke all other
proxies and powers of attorney granted by the undersigned at any time with
respect to such Shares (and all Shares and other securities issued in
Distributions in respect of such Shares), and no subsequent proxy or power of
attorney shall be given or written consent executed (and if given or executed,
shall not be effective) by the undersigned with respect thereto. The undersigned
understands that, in order for Shares to be deemed validly tendered, immediately
upon Purchaser's acceptance of such Shares for payment, Purchaser or its
designee must be able to exercise full voting, consent and other rights with
respect to such Shares and Distributions, including, without limitation, voting
at any meeting of Barrett Resources' stockholders.

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      The undersigned hereby represents and warrants that the undersigned has
full power and authority to tender, sell, assign and transfer the Shares
tendered hereby and all Distributions, and that when such Shares are accepted
for payment by Purchaser, Purchaser will acquire good, marketable and
unencumbered title thereto and to all Distributions, free and clear of all
liens, restrictions, charges and encumbrances, and that none of such Shares or
Distributions will be subject to any adverse claim. The undersigned, upon
request, shall execute and deliver all additional documents deemed by the
Depositary or Purchaser to be necessary or desirable to complete the sale,
assignment and transfer of the Shares tendered hereby and all Distributions. In
addition, the undersigned shall remit and transfer promptly to the Depositary
for the account of Purchaser all Distributions in respect of the Shares tendered
hereby, accompanied by appropriate documentation of transfer, and pending such
remittance and transfer or appropriate assurance thereof, Purchaser shall be
entitled to all rights and privileges as owner of each such Distribution and may
withhold the entire purchase price of the Shares tendered hereby, or deduct from
such purchase price, the amount or value of such Distribution as determined by
Purchaser in its sole discretion.

      No authority herein conferred or agreed to be conferred shall be affected
by, and all such authority shall survive, the death or incapacity of the
undersigned. All obligations of the undersigned hereunder shall be binding upon
the heirs, personal representatives, successors and assigns of the undersigned.
Except as stated in the Offer to Purchase, this tender is irrevocable. See
Section 4 in the Offer to Purchase.

      The undersigned understands that tenders of Shares pursuant to any one of
the procedures described in Section 3 of the Offer to Purchase and in the
instructions hereto will constitute the undersigned's acceptance of the terms
and conditions of the Offer. Purchaser's acceptance of such Shares for payment
will constitute a binding agreement between the undersigned and Purchaser upon
the terms and subject to the conditions of the Offer, as well as the
undersigned's representation and warranty to Purchaser and Barrett Resources
that (i) the undersigned has a net long position in the Shares or equivalent
securities being tendered within the meaning of Rule 14e-4 promulgated under the
Securities Exchange Act of 1934, as amended (the "Exchange Act") and (ii) the
tender of such Shares complies with Rule 14e-4 of the Exchange Act. Without
limiting the foregoing, if the price to be paid in the Offer is amended in
accordance with the Offer, the price to be paid to the undersigned will be the
amended price notwithstanding the fact that a different price is stated in this
Letter of Transmittal. The undersigned recognizes that under certain
circumstances set forth in the Offer to Purchase, Purchaser may not be required
to accept for payment any of the Shares tendered hereby.

      Unless otherwise indicated herein in the box entitled "Special Payment
Instructions," please issue the check for the purchase price of all Shares
purchased, and return all Share Certificates not purchased or not tendered in
the name(s) of the registered holder(s) appearing above in the box entitled
"Description of Shares Tendered." Similarly, unless otherwise indicated in the
box entitled "Special Delivery Instructions," please mail the check for the
purchase price of all Shares purchased and all Share Certificates not tendered
or not purchased (and accompanying documents, as appropriate) to the address(es)
of the registered holder(s) appearing above in the box entitled "Description of
Shares Tendered." In the event that the boxes entitled "Special Payment
Instructions" and "Special Delivery Instruction" are both completed, please
issue the check for the purchase price of all Shares purchased and return all
Share Certificates not purchased or not tendered in the name(s) of, and mail
such check and Share Certificates to, the person(s) so indicated. Unless
otherwise indicated herein in the box entitled "Special Payment Instructions,"
please credit any Shares tendered hereby and delivered by book-entry transfer,
but which are not purchased, by crediting the account at the Book-Entry Transfer
Facility. The undersigned recognizes that Purchaser has no obligation, pursuant
to the Special Payment Instructions, to transfer any Shares from the name of the
registered holder(s) thereof if Purchaser does not purchase any of the Shares
tendered hereby.

      The undersigned understands that Purchaser reserves the right to transfer
or assign, in whole at any time, or in part from time to time, to one or more of
its affiliates, the right to purchase all or any portion of the Shares tendered
pursuant to the Offer, but any such transfer or assignment will not relieve
Purchaser of its obligations under the Offer and will in no way prejudice the
rights of tendering stockholders to receive payment for Shares validly tendered
and accepted for payment pursuant to the Offer.

      The undersigned understands that Purchaser is offering to purchase
16,730,502 shares, and that in the event that more than 16,730,502 Shares are
validly tendered and not withdrawn as of the Expiration Date (as defined in the
Offer to Purchase) and proration of tendered Shares is required, because of the
difficulty of determining the precise

                                        4
   5

number of Shares properly tendered and not withdrawn (due in part to the
guaranteed delivery procedure described under Section 3 of the Offer to
Purchase), the Purchaser does not expect that it will be able to announce the
final results of such proration or pay for any Shares until at least five New
York Stock Exchange trading days after the Expiration Date. Preliminary results
of proration will be announced by press release as promptly as practicable after
the Expiration Date. Stockholders may obtain such preliminary information from
the Information Agent and may be able to obtain such information from their
brokers. Tendering stockholders will not receive payment for Shares accepted for
payment pursuant to the Offer until the final proration factor is known.

                          SPECIAL PAYMENT INSTRUCTIONS
                        (SEE INSTRUCTIONS 1, 5, 6 AND 7)

     To be completed ONLY if Share Certificates not tendered or purchased and/or
the check for the purchase price of the Shares purchased are to be issued in the
name of and sent to someone other than the undersigned, or if Shares tendered by
book-entry transfer which are not purchased are to be returned by credit to an
account maintained at the Book-Entry Transfer Facility other than the account
indicated above.

Issue:

       [ ] Check

           and/or

       [ ] Share Certificates

Name:
- -----------------------------------------------
                                    (PLEASE PRINT)

Address:
- ---------------------------------------------

- ------------------------------------------------------
                               (INCLUDE ZIP CODE)

- ------------------------------------------------------
              (TAXPAYER IDENTIFICATION NO. OR SOCIAL SECURITY NO.)
                   (ALSO COMPLETE SUBSTITUTE FORM W-9 BELOW)

[ ] Credit unpurchased Shares tendered by book-entry transfer to the Book-Entry
    Transfer Facility account set forth below:

- ------------------------------------------------------
                                (ACCOUNT NUMBER)

                         SPECIAL DELIVERY INSTRUCTIONS
                        (SEE INSTRUCTIONS 1, 5, 6 AND 7)

     To be completed ONLY if Share Certificates not tendered or not purchased
and/or the check for the purchase price of the Shares purchased are to be sent
to someone other than the undersigned, or to the undersigned at an address other
than that shown above.

Mail:

       [ ] Check

           and/or

       [ ] Share Certificates

Name:
- -----------------------------------------------
                                    (PLEASE PRINT)

Address:
- ---------------------------------------------

- ------------------------------------------------------
                               (INCLUDE ZIP CODE)

- ------------------------------------------------------
             (TAXPAYER IDENTIFICATION CODE OR SOCIAL SECURITY NO.)

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                                   SIGN HERE
                   (AND PLEASE COMPLETE SUBSTITUTE FORM W-9)

- --------------------------------------------------------------------------------

- --------------------------------------------------------------------------------
                          (SIGNATURE(S) OF HOLDER(S))

Dated:
- --------------------------- , 2001

(Must be signed by registered holder(s) exactly as name(s) appear(s) on Share
Certificate(s) and/or certificates representing Rights, if any, or on a security
position listing or by person(s) authorized to become registered holder(s) by
Share Certificates and documents transmitted herewith. If a signature is by an
officer on behalf of a corporation or by an executor, administrator, trustee,
guardian, attorney-in-fact, agent or other person acting in a fiduciary or
representative capacity, please provide the following information. See
Instructions 1 and 5.)

Name(s):------------------------------------------------------------------------

- --------------------------------------------------------------------------------
                                 (PLEASE PRINT)

Name of Firm:
- --------------------------------------------------------------------------------

Capacity (full title):
- --------------------------------------------------------------------------------

Address:
- --------------------------------------------------------------------------------

- --------------------------------------------------------------------------------
                               (INCLUDE ZIP CODE)

(Area Code) Telephone Number:
- --------------------------------------------------------------------------------

Taxpayer Identification or Social Security No.:
           ---------------------------------------------------------------------
                           (SEE SUBSTITUTE FORM W-9)

                           GUARANTEE OF SIGNATURE(S)
                   (IF REQUIRED -- SEE INSTRUCTIONS 1 AND 5)

Authorized Signature:
- --------------------------------------------------------------------------------

Name:
- --------------------------------------------------------------------------------
                                 (PLEASE PRINT)

Name of Firm:
- --------------------------------------------------------------------------------

Address:
- --------------------------------------------------------------------------------

Zip Code:
- ------------------------------

(Area Code) Telephone No.:
- --------------------------------------------------------------------------------

Dated:
- --------------------------- , 2001

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                                  INSTRUCTIONS

             FORMING PART OF THE TERMS AND CONDITIONS OF THE OFFER

      To complete the Letter of Transmittal, you must do the following:

      - Fill in the box entitled "Description of Shares Being Tendered."

      - Sign and date the Letter of Transmittal in the box entitled "Sign Here."

      - Fill in and sign in the box entitled "Substitute Form W-9" (or, if you
        are a foreign stockholder, request and complete an appropriate Form W-8
        in lieu of Substitute Form W-9)."

      In completing the Letter of Transmittal, you may (but are not required to)
also do the following:

      - If you want the payment for any Shares purchased issued in the name of
        another person, complete the box entitled "Special Payment
        Instructions."

      - If you want any certificate for Shares not tendered or Shares not
        purchased, including as a result of proration, issued in the name of
        another person, complete the box entitled "Special Payment
        Instructions."

      - If you want any payment for Shares or certificate for Shares not
        tendered or purchased, including as a result of proration, delivered to
        an address other than that appearing under your signature, complete the
        box entitled "Special Delivery Instructions."

      - If you complete the box entitled "Special Payment Instructions" or
        "Special Delivery Instructions," you must have your signature guaranteed
        by an Eligible Institution (as defined in Instruction 1 below) unless
        the Letter of Transmittal is signed by an Eligible Institution.

      1.  GUARANTEE OF SIGNATURES.  All signatures on this Letter of Transmittal
must be guaranteed by a bank, broker, dealer, credit union, savings association
or other entity that is a member in good standing of the Securities Transfer
Agents Medallion Program (an "Eligible Institution"), unless (i) this Letter of
Transmittal is signed by the registered holder(s) (which term, for purposes of
this document, shall include any participant in the Book-Entry Transfer Facility
whose name appears on a security position listing as the owner of Shares) of the
Shares tendered hereby and such holder(s) has not completed either the box
entitled "Special Payment Instructions" or the box entitled "Special Delivery
Instructions" herein or (ii) such Shares are tendered for the account of an
Eligible Institution. If a Share Certificate is registered in the name of a
person other than the person signing this Letter of Transmittal, or if payment
is to be made or a Share Certificate not accepted for payment and not tendered
is to be returned to a person other than the registered holder(s), then such
Share Certificate must be endorsed or accompanied by appropriate stock powers,
in either case signed exactly as the name(s) of the registered holder(s) appear
on such Share Certificate, with the signatures on such Share Certificate or
stock powers guaranteed as described above. See Instruction 5.

      2.  DELIVERY OF LETTER OF TRANSMITTAL AND SHARE CERTIFICATES.  This Letter
of Transmittal is to be used either if Share Certificates (or certificates
representing Rights ("Rights Certificates") if any) are to be forwarded herewith
or, unless an Agent's Message (as defined below) is used, if Shares are to be
delivered by book-entry transfer pursuant to the procedure set forth in Section
3 of the Offer to Purchase. Share Certificates representing all physically
tendered Shares, or confirmation of a book-entry transfer, if such procedure is
available, into the Depositary's account at the Book-Entry Transfer Facility
("Book-Entry Confirmation") of all Shares delivered by book-entry transfer
together with a properly completed and duly executed Letter of Transmittal (or
facsimile thereof), or an Agent's Message in the case of book-entry transfer,
and any other documents required by this Letter of Transmittal, must be received
by the Depositary at one of its addresses set forth herein prior to the
Expiration Date of the Offer. If Share Certificates are forwarded to the
Depositary in multiple deliveries, a properly completed and duly executed Letter
of Transmittal must accompany each such delivery.

      Stockholders whose Share Certificates (and/or Rights Certificates, if any)
are not immediately available, who cannot deliver their Share Certificates
and/or Rights Certificates and all other required documents to the Depositary
prior to the Expiration Date of the Offer or who cannot complete the procedure
for delivery by book-entry transfer on a timely basis may tender their Shares
pursuant to the guaranteed delivery procedure described in Section 3 of the

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Offer to Purchase. Pursuant to such procedure: (i) such tender must be made by
or through an Eligible Institution; (ii) a properly completed and duly executed
Notice of Guaranteed Delivery, substantially in the form made available by
Purchaser, must be received by the Depositary prior to the Expiration Date of
the Offer; and (iii) the Share Certificates representing all physically
delivered Shares in proper form for transfer by delivery, or Book-Entry
Confirmation of all Shares and Rights delivered by book-entry transfer, in each
case together with a Letter of Transmittal (or facsimile thereof), properly
completed and duly executed, with any required signature guarantees (or, in the
case of a book-entry transfer, an Agent's Message), and any other documents
required by this Letter of Transmittal, must be received by the Depositary
within three New York Stock Exchange trading days after the date of execution of
such Notice of Guaranteed Delivery, all as described in Section 3 of the Offer
to Purchase.

      The term "Agent's Message" means a message, transmitted by the Book-Entry
Transfer Facility to, and received by, the Depositary and forming a part of the
Book-Entry Confirmation, which states that the Book-Entry Transfer Facility has
received an express acknowledgment from the participants in the Book-Entry
Transfer Facility tendering the Shares that such participant has received this
Letter of Transmittal and agrees to be bound by the terms of this Letter of
Transmittal and that Purchaser may enforce such agreement against such
participant.

      THE METHOD OF DELIVERY OF THIS LETTER OF TRANSMITTAL, SHARE CERTIFICATES,
RIGHTS CERTIFICATES, IF ANY, AND ALL OTHER REQUIRED DOCUMENTS, INCLUDING
DELIVERY THROUGH THE BOOK-ENTRY TRANSFER FACILITY, IS AT THE OPTION AND RISK OF
THE TENDERING STOCKHOLDER, AND THE DELIVERY WILL BE DEEMED MADE ONLY WHEN
ACTUALLY RECEIVED BY THE DEPOSITARY (INCLUDING, IN THE CASE OF A BOOK-ENTRY
TRANSFER, BY BOOK-ENTRY CONFIRMATION). IF DELIVERY IS BY MAIL, REGISTERED MAIL
WITH RETURN RECEIPT REQUESTED, PROPERLY INSURED, IS RECOMMENDED. IN ALL CASES,
SUFFICIENT TIME SHOULD BE ALLOWED TO ENSURE TIMELY DELIVERY.

      No alternative, conditional or contingent tenders will be accepted and no
fractional Shares will be purchased. By execution of this Letter of Transmittal
(or facsimile hereof), all tendering stockholders waive any right to receive any
notice of the acceptance of their Shares for payment.

      3.  INADEQUATE SPACE.  If the space provided herein under "Description of
Shares Tendered" is inadequate, the certificate numbers, the number of Shares
represented by such Share Certificates and the number of Shares tendered should
be listed on a separate signed schedule and attached hereto.

      4.  PARTIAL TENDERS (NOT APPLICABLE TO STOCKHOLDERS WHO TENDER BY
BOOK-ENTRY TRANSFER).  If fewer than all the Shares represented by any Share
Certificate delivered to the Depositary herewith are to be tendered hereby, fill
in the number of Shares which are to be tendered in the box entitled "Number of
Shares Tendered." In such cases, a new certificate representing the remainder of
the Shares that were represented by the Share Certificates delivered to the
Depositary herewith will be sent to each person signing this Letter of
Transmittal, unless otherwise provided in the box entitled "Special Delivery
Instructions" herein, as soon as practicable after the expiration or termination
of the Offer. All Shares represented by Share Certificates delivered to the
Depositary will be deemed to have been tendered unless otherwise indicated.

      5.  SIGNATURES ON LETTER OF TRANSMITTAL, STOCK POWERS AND ENDORSEMENTS.
If this Letter of Transmittal is signed by the registered holder(s) of the
Shares tendered hereby, the signature(s) must correspond with the name(s) as
written on the face of the Share Certificates evidencing such Shares without
alteration, enlargement or any other change whatsoever.

      If any Share tendered hereby is owned of record by two or more persons,
each such person must sign this Letter of Transmittal.

      If any of the Shares tendered hereby are registered in the names of
different holders, it will be necessary to complete, sign and submit as many
separate Letters of Transmittal as there are different registrations of such
Shares.

      If this Letter of Transmittal is signed by the registered holder(s) of the
Shares tendered hereby, no endorsements of Share Certificates or separate stock
powers are required, unless payment is to be made to, or Share Certificates not
tendered or not purchased are to be issued in the name of, a person other than
the registered holder(s), in which case, the Share Certificate(s) representing
the Shares tendered hereby must be endorsed or accompanied by appropriate stock
powers, in either case signed exactly as the name(s) of the registered holder(s)

                                        8
   9

appear on such Share Certificate(s). Signatures on such Share Certificate(s) and
stock powers must be guaranteed by an Eligible Institution.

      If this Letter of Transmittal is signed by a person other than the
registered holder(s) of the Shares tendered hereby, the Share Certificate(s)
representing the Shares tendered hereby must be endorsed or accompanied by
appropriate stock powers, in either case signed exactly as the name(s) of the
registered holder(s) appear(s) on such Share Certificate(s). Signatures on such
Share Certificate(s) and stock powers must be guaranteed by an Eligible
Institution.

      If this Letter of Transmittal or any certificate or stock power is signed
by a trustee, executor, administrator, guardian, attorney-in-fact, officer of a
corporation or other person acting in a fiduciary or representative capacity,
such person should so indicate when signing, and proper evidence satisfactory to
Purchaser of such person's authority to so act must be submitted.

      6.  STOCK TRANSFER TAXES.  Except as otherwise provided in this
Instruction 6, Barrett Resources will pay all stock transfer taxes with respect
to the sale and transfer of any Shares to Purchaser or Purchaser's order
pursuant to the Offer. If, however, payment of the purchase price of any Shares
purchased is to be made to, or Share Certificate(s) representing Shares not
tendered or not purchased are to be issued in the name of, a person other than
the registered holder(s), the amount of any stock transfer taxes (whether
imposed on the registered holder(s), such other person or otherwise) payable on
account of the transfer to such other person will be deducted from the purchase
price of such Shares purchased, unless evidence satisfactory to Barrett
Resources of the payment of such taxes, or exemption therefrom, is submitted.

      EXCEPT AS PROVIDED IN THIS INSTRUCTION 6, IT WILL NOT BE NECESSARY FOR
TRANSFER TAX STAMPS TO BE AFFIXED TO THE SHARE CERTIFICATES REPRESENTING THE
SHARES TENDERED HEREBY.

      7.  SPECIAL PAYMENT AND DELIVERY INSTRUCTIONS.  If a check for the
purchase price of any Shares tendered hereby is to be issued, or Share
Certificate(s) representing Shares not tendered or not purchased, including as a
result of proration, are to be issued, in the name of a person other than the
person(s) signing this Letter of Transmittal or if such check or any such Share
Certificate is to be sent to someone other than the person(s) signing this
Letter of Transmittal or to the person(s) signing this Letter of Transmittal but
at an address other than that shown in the box entitled "Description of Shares
Tendered" herein, the appropriate boxes in this Letter of Transmittal must be
completed. Stockholders delivering Shares tendered hereby by book-entry transfer
may request that Shares not purchased be credited to the account maintained at
the Book-Entry Transfer Facility as such stockholder may designate in the box
entitled "Special Payment Instructions" herein. If no such instructions are
given, all such Shares not purchased will be returned by crediting the same
account at the Book-Entry Transfer Facility as the account from which such
Shares were delivered.

      8.  WAIVER OF CONDITIONS.  Except as otherwise set forth in the Offer to
Purchase, the conditions of the Offer may be waived, in whole or in part, by
Purchaser, in its sole discretion, at any time and from time to time, in the
case of any Shares tendered. See Section 14 of the Offer to Purchase.

      9.  LOST, DESTROYED OR STOLEN CERTIFICATES.  If any Share Certificate(s)
have been lost, destroyed or stolen, the stockholder should promptly contact
EquiServe at 1-800-736-3001 for instructions as to the procedures for replacing
the Share Certificate(s). This Letter of Transmittal and related documents
cannot be processed until the lost, destroyed or stolen certificates have been
replaced and the replacement Share Certificates have been delivered to the
Depositary in accordance with the procedures set forth in Section 3 of the Offer
to Purchase and the instructions contained in this Letter of Transmittal.

      10.  QUESTIONS AND REQUESTS FOR ASSISTANCE OR ADDITIONAL
COPIES.  Questions and requests for assistance may be directed to the
Information Agent or the Dealer Manager at their respective addresses or
telephone numbers set forth below. Additional copies of the Offer to Purchase,
this Letter of Transmittal, the Notice of Guaranteed Delivery and the Guidelines
for Certification of Taxpayer Identification Number on Substitute Form W-9 may
be obtained from the Information Agent or the Dealer Manager or from brokers,
dealers, commercial banks or trust companies.

      11.  BACKUP WITHHOLDING; SUBSTITUTE FORM W-9; FORM W-8.  Each tendering
stockholder is required to provide the Depositary with a correct Taxpayer
Identification Number ("TIN") on the Substitute Form W-9 which is

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provided under "Important Tax Information" below, and to certify, under
penalties of perjury, (1) that such number is correct, (2) that such stockholder
is not subject to backup withholding of Federal income tax and (3) that such
stockholder is a U.S. person. If a tendering stockholder has been notified by
the Internal Revenue Service that such stockholder is subject to backup
withholding, such stockholder must cross out item (2) of the Certification box
of the Substitute Form W-9, unless such stockholder has since been notified by
the Internal Revenue Service that such stockholder is no longer subject to
backup withholding. Failure to provide the requisite information on the
Substitute Form W-9 may subject the tendering stockholder to a $50 penalty
imposed by the Internal Revenue Service and to 31% Federal income tax
withholding on the payment of the purchase price of all Shares purchased from
such stockholder. If the tendering stockholder has not been issued a TIN and has
applied for one or intends to apply for one in the near future, such stockholder
should write "Applied For" in the space provided for the TIN in Part I of the
Substitute Form W-9, and sign and date the Substitute Form W-9 and the
Certificate of Awaiting Taxpayer Identification Number. If "Applied For" is
written in Part I and the Depositary is not provided with a TIN by the time of
the payment of purchase price to the tendering stockholder pursuant to the
Offer, the Depositary will withhold 31% on such payment. Each foreign
stockholder must complete and submit an appropriate Form W-8 in order to be
exempt from the 31% Federal income tax backup withholding due on payments with
respect to the Shares.

IMPORTANT: THIS LETTER OF TRANSMITTAL (OR FACSIMILE THEREOF), TOGETHER WITH ANY
REQUIRED SIGNATURE GUARANTEES, OR, IN THE CASE OF A BOOK-ENTRY TRANSFER, AN
AGENT'S MESSAGE, AND ANY OTHER REQUIRED DOCUMENTS, MUST BE RECEIVED BY THE
DEPOSITARY PRIOR TO THE EXPIRATION OF THE OFFER, AND EITHER SHARE CERTIFICATES
FOR TENDERED SHARES MUST BE RECEIVED BY THE DEPOSITARY OR SHARES MUST BE
DELIVERED PURSUANT TO THE PROCEDURES FOR BOOK-ENTRY TRANSFER, IN EACH CASE PRIOR
TO THE EXPIRATION DATE OF THE OFFER, OR THE TENDERING STOCKHOLDER MUST COMPLY
WITH THE PROCEDURES FOR GUARANTEED DELIVERY.

                           IMPORTANT TAX INFORMATION

      Under federal income tax law, a stockholder whose tendered Shares are
accepted for payment is required to provide the Depositary (as payer) with such
stockholder's correct TIN on Substitute Form W-9 below. If such stockholder is
an individual, the TIN is his or her social security number. If a tendering
stockholder is subject to backup withholding, such stockholder must cross out
item (2) of the Certification box on the Substitute Form W-9. If the Depositary
is not provided with the correct TIN, the stockholder may be subject to a $50
penalty imposed by the Internal Revenue Service. In addition, payments that are
made to such stockholder with respect to Shares purchased pursuant to the Offer
may be subject to backup withholding.

      Certain stockholders (including, among others, all corporations, and
certain foreign individuals) are not subject to these backup withholding and
reporting requirements. In order for a foreign individual to qualify as an
exempt recipient, that stockholder must submit an appropriate Form W-8
certifying to that individual's foreign status. Appropriate Forms W-8 can be
obtained from the Depositary. An exempt stockholder, other than a foreign
individual, should furnish its TIN, write "Exempt" on the face of the Substitute
Form W-9 below, and sign, date and return the Substitute Form W-9 to the
Depositary. See the enclosed Guidelines for Certification of Taxpayer
Identification Number on Substitute Form W-9 for additional instructions.

      If backup withholding applies, the Depositary is required to withhold 31%
of any payments made to the stockholder. Backup withholding is not an additional
tax. Rather, the federal income tax liability of persons subject to backup
withholding will be reduced by the amount of tax withheld. If backup withholding
results in an overpayment of taxes, a refund may be obtained from the Internal
Revenue Service.

PURPOSE OF SUBSTITUTE FORM W-9

      To prevent backup withholding on payments that are made to a stockholder
with respect to Shares purchased pursuant to the Offer, the stockholder is
required to notify the Depositary of such stockholder's correct TIN by
completing the Substitute Form W-9 contained herein and certifying that the TIN
provided on such form is correct (or that such stockholder is awaiting a TIN).

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WHAT NUMBER TO GIVE THE DEPOSITARY

      The stockholder is required to give the Depositary the social security
number or employer identification number of the record owner of the Shares. If
the Shares are in more than one name or are not in the name of the actual owner,
consult the enclosed Guidelines for Certification of Taxpayer Identification
Number on Substitute Form W-9 for additional guidance on which number to report.
If the tendering stockholder has not been issued a TIN and has applied for a
number or intends to apply for a number in the near future, such stockholder
should write "Applied For" in the space provided for in the TIN in Part 1, and
sign and date the Substitute Form W-9. If "Applied For" is written in Part I and
the Depositary is not provided with a TIN by the time of payment, the Depositary
will withhold 31% on all payments of the purchase price, but if a certified TIN
is provided within 60 days, such amounts will be refunded.

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- ---------------------------------------------------------------------------------------------------------------------------
                                        PAYER'S NAME: EQUISERVE TRUST COMPANY, N.A.
- ---------------------------------------------------------------------------------------------------------------------------
SUBSTITUTE                                                                            -------------------------------
 FORM W-9                       PART 1 -- PLEASE PROVIDE YOUR TIN IN THE BOX AT       Social Security Number
 DEPARTMENT OF THE TREASURY     RIGHT AND CERTIFY BY SIGNING AND DATING BELOW         (If awaiting TIN write "Applied For")
 INTERNAL REVENUE SERVICE
                                                                                      OR
                                                                                      -------------------------------
                                                                                      Employer Identification Number
                                                                                      (If awaiting TIN write "Applied For")
                               ------------------------------------------------------------------------------------------
                                PART 2 -- CERTIFICATION -- Under penalties of perjury, I certify that:
PAYER'S REQUEST FOR TAXPAYER    (1) The number shown on this form is my correct Taxpayer Identification Number (or I am
 IDENTIFICATION NUMBER          waiting for a number to be issued for me), and
     ("TIN")                    (2) I am not subject to backup withholding because: (a) I am exempt from backup
                                withholding, or (b) I have not been notified by the Internal Revenue Service (the "IRS")
                                    that I am subject to backup withholding as a result of a failure to report all interest
                                    or dividends, or (c) the IRS has notified me that I am no longer subject to backup
                                    withholding.
                                (3) I am a U.S. person (including a U.S. resident alien).
                               ------------------------------------------------------------------------------------------
                                CERTIFICATION INSTRUCTIONS -- You must cross out item (2) above if you have been notified
                                by the IRS that you are currently subject to backup withholding because of under-reporting
                                interest or dividends on your tax return. However, if after being notified by the IRS that
                                you are subject to backup withholding, you receive another notification from the IRS that
                                you are no longer subject to backup withholding, do not cross out item (2). (Also see
                                instructions in the enclosed Guidelines).
                               ------------------------------------------------------------------------------------------

                                SIGNATURE: ------------------  DATE:-------- , 2001   PART 3 -- Check if you are
                                                                                      awaiting TIN  [ ]
- ---------------------------------------------------------------------------------------------------------------------------


NOTE:  FAILURE TO COMPLETE AND RETURN ONE OF THESE FORMS MAY RESULT IN BACKUP
       WITHHOLDING OF 31% OF ANY CASH PAYMENTS MADE TO YOU PURSUANT TO THE
       OFFER. PLEASE REVIEW THE ENCLOSED GUIDELINES FOR CERTIFICATION OF
       TAXPAYER IDENTIFICATION NUMBER ON SUBSTITUTE FORM W-9 FOR ADDITIONAL
       DETAILS.

       YOU MUST COMPLETE THE FOLLOWING CERTIFICATE IF YOU CHECKED THE BOX IN
       PART 3 OF THE SUBSTITUTE FORM W-9.

             CERTIFICATE OF AWAITING TAXPAYER IDENTIFICATION NUMBER

     I certify under penalties of perjury that a Taxpayer Identification Number
has not been issued to me, and either (1) I have mailed or delivered an
application to receive a Taxpayer Identification Number to the appropriate
Internal Revenue Service Center or Social Security Administration Office or (2)
I intend to mail or deliver an application in the near future. I understand that
if I do not provide a Taxpayer Identification Number to the Depositary by the
time of payment, 31% of all reportable payments made to me thereafter will be
withheld, but that such amounts will be refunded to me if I provide a certified
Taxpayer Identification Number to the Depositary within sixty (60) days.

Signature:
- -------------------------------------------------------------------  Date:
- ------------------------ , 2001

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      Questions and requests for assistance or additional copies of the Offer to
Purchase, this Letter of Transmittal and other tender offer materials may be
directed to the Information Agent or the Dealer Manager as set forth below:

                    The Information Agent for the Offer is:

                                [GEORGESON LOGO]
                          17 State Street, 10th Floor
                               New York, NY 10004
                 BANKS AND BROKERS CALL COLLECT (212) 440-9800
                    ALL OTHERS CALL TOLL FREE (800) 223-2064

                      The Dealer Manager for the Offer is:

                              MERRILL LYNCH & CO.
                          Four World Financial Center
                            New York, New York 10080
                          Call Collect: (212) 236-3790