Exhibit 4.8
                                                                     -----------

                                    GUARANTY

      THIS GUARANTY  (this  "Guaranty") is dated as of the 22nd day of December,
2003,  by  BLUESTEM   PIPELINE,   LLC,  a  Delaware  limited  liability  company
("Guarantor"),  in favor of BANK  ONE,  NA,  with its main  office  in  Chicago,
Illinois,  and each of the other financial  institutions  (1) listed on Schedule
1.1-A to the  Revolving  Credit  Agreement  (as  hereinafter  defined)  as Banks
(collectively, "Revolving Lenders"), and (2) from time to time party to the Term
Credit  Agreement  (as  hereinafter  defined)  as Lenders  (collectively,  "Term
Lenders")  and each of their  respective  successors  and  assigns as  permitted
pursuant to the Revolving  Credit  Agreement  and the Term Credit  Agreement (as
applicable)  (Bank One, NA, acting as both a Revolving  Lender and a Term Lender
but not as Revolving Agent (as hereinafter defined),  Term Agent (as hereinafter
defined),  or Collateral Agent (as hereinafter  defined),  and each of the other
Term  Lenders  and  Revolving  Lenders  are  collectively  referred to herein as
"Noteholders").

                             W I T N E S S E T H:
                             -------------------

      WHEREAS,  Quest  Cherokee,  LLC,  a  Delaware  limited  liability  company
("Borrower"),  Revolving  Lenders,  and Bank One,  NA,  with its main  office in
Chicago,  Illinois, as Administrative Agent thereunder  ("Revolving Agent"), are
parties to that certain Credit Agreement (as amended, restated,  supplemented or
otherwise modified from time to time, the "Revolving Credit  Agreement";  unless
otherwise defined or indicated herein,  all terms used herein with their initial
letter  capitalized  shall have the  meaning  given such terms in the  Revolving
Credit  Agreement)  dated as of December 22, 2003,  pursuant to which  Revolving
Lenders have agreed to make a revolving loan to Borrower and agreed to issue and
participate in letters of credit issued on behalf of Borrower; and

      WHEREAS,  Borrower,  Guarantor,  Term Lenders,  and Bank One, NA, with its
main  office in Chicago,  Illinois,  as Agent  thereunder  ("Term  Agent"),  are
parties to that certain  Senior Term Second Lien Secured  Credit  Agreement  (as
amended,  restated,  supplemented  or otherwise  modified from time to time, the
"Term Credit Agreement" and,  together with the Revolving Credit Agreement,  the
"Credit  Agreements" and, each individually,  a "Credit  Agreement") dated as of
December  22,  2003,  pursuant to which Term  Lenders have agreed to make a term
loan to Borrower; and

      WHEREAS,  certain of the relative rights and remedies of Revolving Lenders
and  Term  Lenders  are  set  forth  in  that  certain   Collateral  Agency  and
Intercreditor  Agreement  dated as of December  22, 2003 among Bank One,  NA, as
Collateral Agent thereunder  ("Collateral Agent"),  Revolving Agent, Term Agent,
Noteholders,  Borrower and  Guarantor  (as amended,  restated,  supplemented  or
otherwise modified from time to time, the "Intercreditor Agreement"); and

      WHEREAS,  pursuant  to the terms of the  Credit  Agreements,  Borrower  is
obligated to deliver this Guaranty executed by Guarantor; and

      WHEREAS,  the board of directors of Guarantor has determined that valuable
benefits  will be  derived by it as a result of the  Credit  Agreements  and the
extension of credit made (and to be made) by Noteholders thereunder; and


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      WHEREAS,   the  board  of  directors  of  Guarantor  has  determined  that
Guarantor's execution,  delivery and performance of this Guaranty may reasonably
be  expected  to benefit  Guarantor,  directly  or  indirectly,  are in the best
interests  of  Guarantor,  and  are  necessary  or  convenient  to the  conduct,
promotion or attainment of Borrower's business; and

      WHEREAS, Guarantor has further determined that the benefits accruing to it
from each Credit Agreement exceed Guarantor's  anticipated  liability under this
Guaranty.

      NOW, THEREFORE, for valuable consideration, the receipt and sufficiency of
which are hereby  acknowledged  and confessed,  Guarantor  hereby  covenants and
agrees as follows:

     1. Guarantor hereby absolutely and  unconditionally  guarantees the prompt,
complete  and full payment when due, no matter how such shall become due, of the
Obligations,  and further  guarantees  that  Borrower  will  properly and timely
perform  the  Obligations.   Notwithstanding  any  contrary  provision  in  this
Guaranty, however, Guarantor's maximum liability under this Guaranty is limited,
to the  extent,  if any,  required  so that  its  liability  is not  subject  to
avoidance  under  applicable  Debtor  Relief  Laws (as such term is  defined  in
Paragraph 8 hereof). As used herein, "Obligations" shall mean, collectively, all
Obligations,  as such term is defined in the Revolving Credit Agreement, and all
Obligations, as such term is defined in the Term Credit Agreement.

     2. If Guarantor is or becomes liable for any indebtedness owing by Borrower
to any Noteholder by  endorsement  or otherwise  than under this Guaranty,  such
liability shall not be in any manner impaired or affected hereby, and the rights
of  Noteholders  hereunder  shall be cumulative of any and all other rights that
Noteholders may ever have against  Guarantor.  The exercise by any Noteholder of
any  right or remedy  hereunder  or under  any  other  instrument,  at law or in
equity,  shall not preclude the  concurrent or subsequent  exercise of any other
right or remedy.

     3. In the event of default by  Borrower in payment of the  Obligations,  or
any part thereof,  when such Obligations become due, either by their terms or as
the result of the  exercise  of any power to  accelerate,  Guarantor  shall,  on
demand,  and without  further  notice of dishonor and without any notice  having
been given to Guarantor previous to such demand of the acceptance by Noteholders
of this  Guaranty or of the creating or incurring of such  Obligations,  pay the
amount due thereon to Noteholders  as set forth in this  Guaranty,  and it shall
not be  necessary  for any  Noteholder,  in order to  enforce  such  payment  by
Guarantor,  first, to institute suit or exhaust its remedies against Borrower or
others liable on such Obligations, to have Borrower joined with Guarantor in any
suit brought under this Guaranty or to enforce their rights against any security
which shall ever have been given to secure such indebtedness; provided, however,
that in the event any Noteholder  elects to enforce and/or exercise any remedies
they may possess  with  respect to any  security  for the  Obligations  prior to
demanding  payment from  Guarantor,  Guarantor  shall  nevertheless be obligated
hereunder for any and all sums still owing to Noteholders on the Obligations and
not repaid or recovered incident to the exercise of such remedies.


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     4.  Notice to  Guarantor  of the  acceptance  of this  Guaranty  and of the
making,  renewing or assignment of the  Obligations  and each item thereof,  are
hereby expressly waived by Guarantor.

     5. Each  payment  on the  Obligations  shall be deemed to have been made by
Borrower  unless  express  written notice is given to Noteholders at the time of
such payment that such payment is made by Guarantor as specified in such notice.

     6. If all or any part of the Obligations at any time are secured, Guarantor
agrees that Collateral Agent and/or Noteholders may at any time and from time to
time, at their  discretion  and with or without  valuable  consideration,  allow
substitution   or  withdrawal  of  collateral  or  other  security  and  release
collateral  or other  security or  compromise  or settle any amount due or owing
under the  Credit  Agreements  or amend or modify in whole or in part the Credit
Agreements or any Loan Paper executed in connection  with the Credit  Agreements
without  impairing  or  diminishing  the  obligations  of  Guarantor  hereunder.
Guarantor  further  agrees that if Borrower  executes in favor of any Noteholder
any collateral agreement, mortgage or other security instrument, the exercise by
any Noteholder of any right or remedy thereby conferred on such Noteholder shall
be wholly  discretionary with such Noteholder,  and that the exercise or failure
to  exercise  any such right or remedy  shall in no way impair or  diminish  the
obligation of Guarantor hereunder. Guarantor further agrees that Noteholders and
Collateral  Agent shall not be liable for their  failure to use diligence in the
collection  of the  Obligations  or in  preserving  the  liability of any Person
liable for the Obligations, and Guarantor hereby waives presentment for payment,
notice  of  nonpayment,   protest  and  notice  thereof   (including  notice  of
acceleration),  and diligence in bringing suits against any Person liable on the
Obligations,  or any part  thereof.  As used herein,  "Loan  Papers" shall mean,
collectively,  all Loan Papers,  as such term is defined in the Revolving Credit
Agreement,  and all Loan  Documents,  as such term is defined in the Term Credit
Agreement.

     7. Guarantor agrees that Noteholders,  in their  discretion,  may (a) bring
suit against all guarantors (including, without limitation, Guarantor hereunder)
of the Obligations jointly and severally or against any one or more of them, (b)
compound  or  settle  with  any  one  or  more  of  such   guarantors  for  such
consideration  as  Noteholders  may deem proper,  and (c) release one or more of
such guarantors from liability  hereunder,  and that no such action shall impair
the rights of  Noteholders  to collect the  Obligations  (or the unpaid  balance
thereof) from other such guarantors of the  Obligations,  or any of them, not so
sued,  settled  with  or  released.  Guarantor  agrees,  however,  that  nothing
contained in this paragraph,  and no action by Noteholders  permitted under this
paragraph,  shall in any way affect or impair the rights or  obligations of such
guarantors among themselves.

     8. Guarantor  represents and warrants to each Noteholder that (a) Guarantor
is a limited  liability  company duly  organized and validly  existing under the
laws of the State of Delaware;  (b) Guarantor  possesses all requisite authority
and power to  authorize,  execute,  deliver  and  comply  with the terms of this
Guaranty;  (c) this  Guaranty  has been  duly  authorized  and  approved  by all
necessary  action on the part of Guarantor  and  constitutes a valid and binding
obligation of Guarantor  enforceable in accordance with its terms, except as (1)
the enforcement thereof may be limited by applicable Debtor Relief Laws, and (2)
the availability of equitable remedies may be limited by equitable principles of
general applicability; and (d) no approval or


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consent of any court or governmental  entity is required for the  authorization,
execution, delivery or compliance with this Guaranty which has not been obtained
(and copies thereof  delivered to  Noteholders).  As used in this Guaranty,  the
term "Debtor  Relief  Laws" means the  Bankruptcy  Code of the United  States of
America  and all  other  applicable  liquidation,  conservatorship,  bankruptcy,
moratorium, rearrangement,  receivership, insolvency, reorganization, suspension
of payments or similar debtor relief laws from time to time in effect  affecting
the rights of creditors generally.

     9. Guarantor  covenants and agrees that until the  Obligations are paid and
performed in full, it will (a) at all times maintain its existence and authority
to transact business in any state or jurisdiction where Guarantor has assets and
operations,  except  where the failure to maintain  such  existence or authority
would not have a Material  Adverse Effect,  (b) promptly  deliver to Noteholders
and to Collateral Agent such information respecting its business affairs, assets
and  liabilities  as  Noteholders  may  reasonably  request,  and (c)  duly  and
punctually  observe and perform all covenants  applicable to Guarantor under the
Credit Agreements and the other Loan Papers.  The failure of Guarantor to comply
with the terms of this paragraph  shall be an Event of Default under each Credit
Agreement.

     10. This Guaranty is for the benefit of Noteholders,  their  successors and
assigns,  and in the event of an assignment by Noteholders (or their  successors
or assigns) of the  Obligations,  or any part  thereof,  the rights and benefits
hereunder,  to the extent  applicable  to the  Obligations  so assigned,  may be
transferred with such  Obligations.  This Guaranty is binding upon Guarantor and
its successors and assigns.

     11. No modification,  consent, amendment or waiver of any provision of this
Guaranty,  nor  consent  to any  departure  by  Guarantor  therefrom,  shall  be
effective unless the same shall be in writing and signed by each Noteholder, and
then shall be effective  only in the  specific  instance and for the purpose for
which given.  No notice to or demand on Guarantor in any case shall,  of itself,
entitle  Guarantor to any other or further  notice or demand in similar or other
circumstances.  No delay or omission by  Noteholders  in exercising any power or
right hereunder shall impair any such right or power or be construed as a waiver
thereof or any acquiescence therein, nor shall any single or partial exercise of
any such power preclude other or further  exercise  thereof,  or the exercise of
any other  right or power  hereunder.  All rights and  remedies  of  Noteholders
hereunder are  cumulative of each other and of every other right or remedy which
Noteholders  may otherwise  have at law or in equity or under any other contract
or  document,  and the  exercise  of one or more  rights or  remedies  shall not
prejudice or impair the  concurrent  or  subsequent  exercise of other rights or
remedies.

     12. No provision herein or in any promissory note,  instrument or any other
Loan Paper executed by Borrower or Guarantor  evidencing the  Obligations  shall
require  the  payment  or permit the  collection  of  interest  in excess of the
Maximum  Lawful Rate.  If any excess of interest in such respect is provided for
herein or in any such promissory note, instrument,  or any other Loan Paper, the
provisions of this paragraph  shall govern,  and neither  Borrower nor Guarantor
shall be obligated  to pay the amount of such  interest to the extent that it is
in excess of the amount  permitted by law. The intention of the parties being to
conform strictly to any applicable federal or state usury laws now in force, all
promissory  notes,  instruments  and other Loan  Papers  executed by Borrower or
Guarantor evidencing the Obligations shall be held subject


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to  reduction  to the amount  allowed  under said usury laws as now or hereafter
construed by the courts having jurisdiction.

     13. If  Guarantor  should  breach or fail to perform any  provision of this
Guaranty,  Guarantor agrees to pay Noteholders all costs and expenses (including
court  costs and  reasonable  attorneys  fees)  incurred by  Noteholders  in the
enforcement hereof.

     14. (a) The liability of Guarantor  under this Guaranty  shall in no manner
be impaired,  affected or released by the insolvency,  bankruptcy,  making of an
assignment for the benefit of creditors, arrangement,  compensation, composition
or readjustment of Borrower, or any proceedings affecting the status,  existence
or assets of  Borrower or other  similar  proceedings  instituted  by or against
Borrower and affecting the assets of Borrower.

         (b) Guarantor acknowledges and agrees  that any interest on any portion
of  the  Obligations  which  accrues  after  the  commencement of any proceeding
referred  to in clause (a) of this  Paragraph  14 above (or,  if interest on any
portion of the Obligations ceases to accrue by operation of law by reason of the
commencement  of said  proceeding,  such  interest as would have accrued on such
portion of the Obligations if said  proceedings had not been commenced) shall be
included in the Obligations because it is the intention of Guarantor, Collateral
Agent and  Noteholders  that the  Obligations  which are guaranteed by Guarantor
pursuant to this Guaranty should be determined without regard to any rule of law
or  order  which  may  relieve  Borrower  of any  portion  of such  Obligations.
Guarantor will permit any trustee in bankruptcy, receiver, debtor in possession,
assignee for the benefit of creditors or similar  Person to pay  Noteholders  or
Collateral  Agent,  or allow the claim of  Noteholders  or  Collateral  Agent in
respect of, any such interest  accruing after the date on which such  proceeding
is commenced.

         (c) In the event that all or any portion of the Obligations are paid by
Borrower,  the  obligations of Guarantor  hereunder shall continue and remain in
full  force and effect or be  reinstated,  as the case may be, in the event that
all or any part of such  payment(s)  are  rescinded  or  recovered  directly  or
indirectly from Collateral  Agent or any Noteholder as a preference,  fraudulent
transfer or otherwise, and any such payments which are so rescinded or recovered
shall constitute Obligations for all purposes under this Guaranty.

     15.  Guarantor  understands  and agrees  that any amounts of  Guarantor  on
account with any Noteholder may, after the occurrence and during the continuance
of an Event of  Default,  be offset to  satisfy  the  obligations  of  Guarantor
hereunder. Any Noteholder that offsets any such amounts against such obligations
shall take reasonable efforts to promptly notify Guarantor of such action.

     16.  Guarantor   hereby   subordinates  and  makes  inferior  any  and  all
indebtedness  now or at any time  hereafter owed by Borrower to Guarantor to the
Obligations  and agrees,  after the occurrence  and during the  continuance of a
Default  or an Event of Default  under and as  defined  in either the  Revolving
Credit Agreement or the Term Credit  Agreement,  or any event which with notice,
lapse of time, or both,  would constitute a Default or an Event of Default under
and as defined in either  the  Revolving  Credit  Agreement  or the Term  Credit
Agreement,  not to permit  Borrower to repay, or to accept payment from Borrower
of, such  indebtedness  or any part thereof without the prior written consent of
Noteholders.


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     17. During the period that Revolving Lenders have any commitment to lend or
participate  in Letter of Credit  Exposure (as defined in the  Revolving  Credit
Agreement), or any amount payable under any Note remains unpaid or any Letter of
Credit (as defined in the Revolving Credit Agreement) remains  outstanding,  and
throughout any additional  preferential  period  subsequent  thereto,  Guarantor
shall not exercise any rights of subrogation to which Guarantor may otherwise be
entitled  against  Borrower,  or any other  guarantor of the  Obligations,  as a
result of any payment made by Guarantor pursuant to this Guaranty.

     18. As of the date  hereof,  the fair  saleable  value of the  property  of
Guarantor is greater than the total amount of liabilities  (including contingent
and unliquidated  liabilities) of Guarantor, and Guarantor is able to pay all of
its  liabilities  as  such  liabilities  mature  and  Guarantor  does  not  have
unreasonably  small capital  within the meaning of Section 548, Title 11, United
States Code,  as amended.  In computing  the amount of  contingent or liquidated
liabilities,  such  liabilities have been computed at the amount which, in light
of all the facts and  circumstances  existing as of the date hereof,  represents
the  amount  that can  reasonably  be  expected  to become an actual or  matured
liability.

     19. If any  provision  of this  Guaranty is held to be illegal,  invalid or
unenforceable,  under present or future Laws  effective  during the term hereof,
such provision  shall be fully  severable,  this Guaranty shall be construed and
enforced as if such  illegal,  invalid,  or  unenforceable  provision  had never
comprised a part hereof,  and the  remaining  provisions  hereof shall remain in
full force and effect and shall not be  affected  by the  illegal,  invalid,  or
unenforceable  provision or by its severance herefrom.  Furthermore,  in lieu of
such  illegal,   invalid,  or  unenforceable  provision  there  shall  be  added
automatically as a part of this Guaranty a provision as similar in terms to such
illegal,  invalid,  or unenforceable  provision as may be possible and be legal,
valid and enforceable.

     20. (a) Guarantor  hereby  irrevocably  submits to the  jurisdiction of any
Texas State or Federal court sitting in the Northern  District of Texas over any
action or  proceeding  arising out of or relating to this  Guaranty or any other
Loan Paper, and Guarantor hereby  irrevocably  agrees that all claims in respect
of such action or proceeding  may be heard and determined in such Texas State or
Federal  court.  Guarantor  agrees  that a final  judgment on any such action or
proceeding  shall be conclusive  and may be enforced in other  jurisdictions  by
suit on the judgment or in any other manner provided by Law.

         (b) Nothing in this  Paragraph 20 shall affect any right of Noteholders
to bring any action or proceeding  against any Guarantor or their  properties in
the courts of any other jurisdictions.

         (c) To  the  extent  that  Guarantor  has  or hereafter may acquire any
immunity  from  jurisdiction  of any  court or from any legal  process  (whether
through service or notice,  attachment  prior to judgment,  attachment in aid of
execution,  execution  or  otherwise)  with  respect to itself or its  property,
Guarantor hereby  irrevocably waives such immunity in respect of its obligations
under this Guaranty and the other Loan Papers.

     21. THIS  GUARANTY  AND THE OTHER LOAN PAPERS  COLLECTIVELY  REPRESENT  THE
FINAL AGREEMENT BY AND AMONG NOTEHOLDERS,


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COLLATERAL AGENT AND GUARANTOR AND MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR,
CONTEMPORANEOUS,  OR  SUBSEQUENT  ORAL  AGREEMENTS  OF  NOTEHOLDERS,  AGENT  AND
GUARANTOR. THERE ARE NO UNWRITTEN ORAL AGREEMENTS AMONG NOTEHOLDERS,  COLLATERAL
AGENT AND GUARANTOR.

     22. EACH NOTEHOLDER, BY ITS ACCEPTANCE OF THIS GUARANTY, AND GUARANTOR, FOR
ITSELF,  ITS  SUCCESSORS AND ASSIGNS,  HEREBY  IRREVOCABLY  AND  UNCONDITIONALLY
WAIVE, TO THE FULLEST EXTENT PERMITTED BY LAW, TRIAL BY JURY IN ANY LEGAL ACTION
OR PROCEEDING  RELATING TO THIS GUARANTY OR ANY OF THE OTHER LOAN PAPERS AND ANY
COUNTERCLAIM THEREIN.

     23.  THIS  GUARANTY  AND THE  OTHER  LOAN  PAPERS  SHALL  BE  CONSTRUED  IN
ACCORDANCE WITH AND GOVERNED BY THE LAWS OF THE STATE OF TEXAS.

     EXECUTED and effective as of the date first above written.

                                        GUARANTOR:

                                        BLUESTEM PIPELINE, LLC, a Delaware
                                        limited liability company


                                        By:    /s/ Jerry Cash
                                               --------------------------------
                                        Name:  Jerry D. Cash
                                        Title: Manager



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