WHEN RECORDED RETURN TO:
VINSON & ELKINS L.L.P.
First City Tower, Suite 3562
1001 Fannin Street
Houston, TX 77002-6760
Attn: Linda Daugherty

                          (Texas Oil & Gas Properties)
               MORTGAGE, DEED OF TRUST, ASSIGNMENT OF PRODUCTION,
                   SECURITY AGREEMENT AND FINANCING STATEMENT



                                      FROM



                            TESORO E&P COMPANY, L.P.
                                  as Mortgagor



                                       TO



                            BRIAN MALONE, AS TRUSTEE



                               FOR THE BENEFIT OF



                    BANQUE PARIBAS, AS ADMINISTRATIVE AGENT,
                                  as Mortgagee


                               TABLE OF CONTENTS

                                   ARTICLE I

                     Grant of Lien and Indebtedness Secured

    Section 1.01   Grant of Liens. . . . . . . . . . . . . . . .1
    Section 1.02   Grant of Security Interest. . . . . . . . . .4
    Section 1.03   Indebtedness Secured. . . . . . . . . . . . .4
    Section 1.04   Fixture Filing, Etc.. . . . . . . . . . . . .5
    Section 1.05   Defined Terms . . . . . . . . . . . . . . . .5

                                   ARTICLE II

                            Assignment of Production

    Section 2.01   Assignment. . . . . . . . . . . . . . . . . .5
    Section 2.02   Rights Under Texas Act. . . . . . . . . . . .6
    Section 2.03   No Modification of Payment Obligations. . . .6

                                  ARTICLE III

                   Representations, Warranties and Covenants

    Section 3.01   Title . . . . . . . . . . . . . . . . . . . .7
    Section 3.02   Defend Title. . . . . . . . . . . . . . . . .7
    Section 3.03   Not a Foreign Person. . . . . . . . . . . . .7
    Section 3.04   Power to Create Lien and Security . . . . . .7
    Section 3.05   Revenue and Cost Bearing Interest . . . . . .8
    Section 3.06   Rentals Paid; Leases in Effect. . . . . . . .8
    Section 3.07   Operation of Mortgaged Property, Etc. . . . .8
    Section 3.08   Operation By Third Parties. . . . . . . . . .9
    Section 3.09   Abandon, Sales. . . . . . . . . . . . . . . .9
    Section 3.10   Failure to Perform. . . . . . . . . . . . . .9

                                   ARTICLE IV

                              Rights and Remedies

    Section 4.01   Event of Default. . . . . . . . . . . . . . 10
    Section 4.02   Foreclosure and Sale. . . . . . . . . . . . 10
    Section 4.03   Substitute Trustees and Agents. . . . . . . 11
    Section 4.04   Judicial Foreclosure; Receivership. . . . . 11
    Section 4.05   Foreclosure for Installments. . . . . . . . 11
    Section 4.06   Separate Sales. . . . . . . . . . . . . . . 12
    Section 4.07   Possession of Mortgaged Property. . . . . . 12


    Section 4.08   Occupancy After Foreclosure . . . . . . . . 12
    Section 4.09   Remedies Cumulative, Concurrent and
                    Nonexclusive . . . . . . . . . . . . . . . 13
    Section 4.10   No Release of Obligations . . . . . . . . . 13
    Section 4.11   Release of and Resort to Collateral . . . . 13
    Section 4.12   Waiver of Redemption, Notice and
                    Marshalling of Assets, Etc . . . . . . . . 13
    Section 4.13   Discontinuance of Proceedings . . . . . . . 14
    Section 4.14   Application of Proceeds . . . . . . . . . . 14
    Section 4.15   Resignation of Operator . . . . . . . . . . 14
    Section 4.16   Indemnity . . . . . . . . . . . . . . . . . 15

                                   ARTICLE V

                                  The Trustee

    Section 5.01   Duties, Rights, and Powers of Trustee . . . 15
    Section 5.02   Successor Trustee . . . . . . . . . . . . . 16
    Section 5.03   Retention of Moneys . . . . . . . . . . . . 16

                                   ARTICLE VI

                                 Miscellaneous

    Section 6.01   Instrument Construed as Mortgage, Etc.. . . 16
    Section 6.02   Release of Mortgage . . . . . . . . . . . . 17
    Section 6.03   Severability. . . . . . . . . . . . . . . . 17
    Section 6.04   Successors and Assigns of Parties . . . . . 17
    Section 6.05   Satisfaction of Prior Encumbrance . . . . . 17
    Section 6.06   Subrogation of Trustee. . . . . . . . . . . 17
    Section 6.07   Nature of Covenants . . . . . . . . . . . . 18
    Section 6.08   Notices . . . . . . . . . . . . . . . . . . 18
    Section 6.09   Counterparts. . . . . . . . . . . . . . . . 18
    Section 6.10   Exculpation Provisions. . . . . . . . . . . 18

    Exhibit A -    Mortgaged Property

                                      -ii-

               MORTGAGE, DEED OF TRUST, ASSIGNMENT OF PRODUCTION,
                   SECURITY AGREEMENT AND FINANCING STATEMENT


    This MORTGAGE, DEED OF  TRUST,  ASSIGNMENT OF PRODUCTION, SECURITY AGREEMENT
AND FINANCING STATEMENT (this "Mortgage") is entered into as  of  the  effective
time  and  date hereinafter stated (the "Effective Date") by TESORO E&P COMPANY,
L.P., a Delaware limited liability  company,  whose address for notice hereunder
is 8700 Tesoro Drive, San Antonio, Texas 78217 ("Mortgagor"), for the benefit of
BANQUE PARIBAS, as Administrative Agent for the benefit of the Issuing Banks and
the Lenders, with offices and banking quarters at 1200 Smith Street, Suite 3100,
Houston, Texas 77002 ("Mortgagee").  Any capitalized term used but  not  defined
in this Mortgage shall have the meaning assigned to such term in the hereinafter
defined Credit Agreement.

                                R E C I T A L S:

    A.   On  even  date  herewith, Tesoro Petroleum Corporation (the "Company"),
Mortgagee, The Bank of Nova Scotia, individually and as Documentation Agent, and
the  other  financial  institutions  parties  thereto  are  executing  a  Credit
Agreement (as amended from time to time, the "Credit Agreement").

    B.   The Lenders and Issuing Banks  have conditioned their obligations under
the Credit Agreement upon the  execution  and  delivery  by  Mortgagor  of  this
Mortgage, and Mortgagor has agreed to enter into this Mortgage.

    C.   Therefore,  in  order  to  comply  with the terms and conditions of the
Credit Agreement and for other good  and valuable consideration, the receipt and
sufficiency of which are  hereby  acknowledged,  Mortgagor  hereby  agrees  with
Mortgagee as follows:


                                   ARTICLE I

                     Grant of Lien and Indebtedness Secured

    Section 1.01   Grant  of  Liens.   To secure payment of the Indebtedness (as
hereinafter defined) and the performance of the covenants and obligations herein
contained, Mortgagor does by these presents hereby GRANT, BARGAIN, SELL, ASSIGN,
MORTGAGE, TRANSFER and CONVEY unto  Brian  Malone of Houston, Texas, as Trustee,
whose address for notice hereunder is 1200 Smith Street,  Suite  3100,  Houston,
Texas  77002  ("Trustee")  and  Trustee's  successors  and  substitutes in trust
hereunder, for the use and benefit of Mortgagee, the real and personal property,
rights, titles, interests and estates  described in the following paragraphs (a)
through (g) (collectively called the "Mortgaged Property"):

    (a)  All rights,  titles,  interests  and  estates  now  owned  or hereafter
acquired by Mortgagor in and to the oil and gas leases and/or oil, gas and other
mineral leases and other interests  and  estates  and  the  lands  and  premises
covered or affected thereby which are described

on  Exhibit  A  hereto (collectively called the "Hydrocarbon Property") or which
Hydrocarbon Property is  otherwise  referred  to  herein,  and specifically, but
without  limitation,  the  undivided  interests  of  Mortgagor  which  are  more
particularly described on attached Exhibit A.

    (b)  All rights, titles,  interests  and  estates  now  owned  or  hereafter
acquired  by  Mortgagor  in and to (i) the properties now or hereafter pooled or
unitized with the Hydrocarbon  Property;  (ii)  all presently existing or future
unitization, communitization, pooling  agreements  and  declarations  of  pooled
units  and  the  units created thereby (including, without limitation, all units
created under orders, regulations, rules or  other official acts of any Federal,
State or other governmental body or agency having  jurisdiction  and  any  units
created solely among working interest owners pursuant to operating agreements or
otherwise)  which  may  affect  all  or  any portion of the Hydrocarbon Property
including, without limitation, those units which may be described or referred to
on attached Exhibit A; (iii) all operating agreements, production sales or other
contracts, farmout  agreements,  farm-in  agreements,  area  of  mutual interest
agreements, equipment leases and other agreements described or  referred  to  in
this Mortgage or which relate to any of the Hydrocarbon Property or interests in
the  Hydrocarbon Property described or referred to herein or on attached Exhibit
A or to the production, sale, purchase, exchange, processing, handling, storage,
transporting or marketing  of  the  Hydrocarbons  (hereinafter  defined) from or
attributable to such Hydrocarbon Property or  interests;  (iv)  all  geological,
geophysical,  engineering,  accounting,  title,  legal,  and  other technical or
business data  concerning  the  Mortgaged  Property,  the  Hydrocarbons, and all
books, files, records, magnetic media, computer  records,  and  other  forms  of
recording  or  obtaining  access  to such data; and (v) the Hydrocarbon Property
described on  attached  Exhibit  A  and  covered  by  this  Mortgage even though
Mortgagor's interests therein be incorrectly described or  a  description  of  a
part  or  all  of  such Hydrocarbon Property or Mortgagor's interests therein be
omitted; it being intended by Mortgagor and Mortgagee herein to cover and affect
hereby all interests which Mortgagor may now own or may hereafter acquire in and
to the Hydrocarbon Property notwithstanding  that  the interests as specified on
Exhibit A may be limited to particular lands,  specified  depths  or  particular
types  of  property interests, but specifically excluding other Property outside
of those described on  Exhibit  A  hereto  and  not  intended  to be part of the
Hydrocarbon Property.

    (c)  All rights, titles,  interests  and  estates  now  owned  or  hereafter
acquired  by  Mortgagor  in  and  to  all  oil, gas, casinghead gas, condensate,
distillate, liquid hydrocarbons, gaseous  hydrocarbons  and all products refined
therefrom and all other minerals (collectively called the "Hydrocarbons") in and
under and  which  may  be  produced  and  saved  from  or  attributable  to  the
Hydrocarbon  Property,  the  lands  pooled or unitized therewith and Mortgagor's
interests therein, including all oil  in  tanks  and all rents, issues, profits,
proceeds, products, revenues and  other  income  from  or  attributable  to  the
Hydrocarbon  Property,  the  lands  pooled or unitized therewith and Mortgagor's
interests therein which are subjected or  required  to be subjected to the liens
and security interests of this Mortgage and including specifically  but  without
limitation  all  liens  and  security  interests  in  such Hydrocarbons securing
payment of proceeds resulting from the sale of Hydrocarbons.

                                      -2-

    (d)  All tenements, hereditaments,  appurtenances  and properties in anywise
appertaining, belonging, affixed or  incidental  to  the  Hydrocarbon  Property,
rights, titles, interests and estates described or referred to in paragraphs (a)
and  (b)  above,  which  are  now  owned  or  which may hereafter be acquired by
Mortgagor,  including,  without  limitation,  any  and  all  property,  real  or
personal, now owned or hereafter acquired and situated upon, used, held for use,
or useful in connection with  the  operating,  working  or development of any of
such Hydrocarbon Property or the lands pooled or unitized  therewith  (excluding
drilling rigs, trucks, automotive equipment or other personal property which may
be taken to the premises for the purpose of drilling a well or for other similar
temporary  uses) and including any and all oil wells, gas wells, injection wells
or other  wells,  buildings,  structures,  field  separators,  liquid extraction
plants, plant compressors, pumps,  pumping  units,  pipelines,  sales  and  flow
lines,   gathering   systems,  field  gathering  systems,  salt  water  disposal
facilities, tanks and tank batteries,  fixtures, valves, fittings, machinery and
parts,  engines,  boilers,  meters,  apparatus,  equipment,  appliances,  tools,
implements, cables, wires, towers, casing,  tubing  and  rods,  surface  leases,
rights-of-way,  easements, servitudes, licenses and other surface and subsurface
rights together with all  additions, substitutions, replacements, accessions and
attachments to any and all of the foregoing properties.

    (e)  Any property that may from time to time hereafter, by  delivery  or  by
writing  of  any  kind, be subjected to the lien and security interest hereof by
Mortgagor; and the Trustee is hereby authorized  to receive the same at any time
as additional security hereunder.

    (f)  All of the rights, titles and interests of every nature whatsoever  now
owned  or  hereafter  acquired  by  Mortgagor in and to the Hydrocarbon Property
rights, titles,  interests  and  estates  and  every  part  and  parcel thereof,
including,  without  limitation,  the  Hydrocarbon  Property   rights,   titles,
interests  and  estates  as  the  same  may  be enlarged by the discharge of any
payments out of  production  or  by  the  removal  of  any  charges or Permitted
Encumbrances (as hereinafter defined in  Section  3.01)  to  which  any  of  the
Hydrocarbon  Property  rights,  titles,  interests  or  estates  are subject, or
otherwise; all rights  of  Mortgagor  to  liens  and security interests securing
payment of proceeds from the sale of production  from  the  Mortgaged  Property,
including,  but  not  limited to, those liens and security interests provided in
Tex. Bus. & Com. Code Ann.  9.319  (Tex.  UCC) (Vernon Supp.  1989) ("9.319 Tex.
UCC"), as amended from time to time; together with  any  and  all  renewals  and
extensions  of  any  of  the  Hydrocarbon  Property rights, titles, interests or
estates; all contracts and  agreements  supplemental  to  or amendatory of or in
substitution for the contracts and agreements described or mentioned above;  and
any  and all additional interests of any kind hereafter acquired by Mortgagor in
and to the Hydrocarbon Property rights, titles, interests or estates.

    (g)  All  accounts,   contract   rights,   inventory,  general  intangibles,
insurance contracts and insurance proceeds constituting a part of,  relating  to
or  arising  out of those portions of the Mortgaged Property which are described
in paragraphs (a) through (f) above  and  all  proceeds and products of all such
portions of the Mortgaged Property and payments in lieu of production  (such  as
"take or pay" payments), whether such proceeds or payments are goods, money,

                                      -3-

documents,   instruments,   chattel   paper,   securities,   accounts,   general
intangibles, fixtures, real property, or other assets.

    Any fractions or percentages specified on attached Exhibit A in referring to
Mortgagor's  interests  are  solely  for  purposes  of  the  warranties  made by
Mortgagor pursuant to Section  3.01  hereof  and  shall  in  no manner limit the
quantum  of  interest  affected  by  this  Section  1.01  with  respect  to  any
Hydrocarbon Property or with respect to any unit  or  well  identified  on  said
Exhibit A.

    TO  HAVE  AND  TO  HOLD  the  Mortgaged Property unto the Trustee and to his
successors and  assigns  forever  to  secure  the  payment  of  the Indebtedness
(hereinafter  defined)  and  to  secure  the  performance  of   the   covenants,
agreements, and obligations of the Mortgagor herein contained.

    Section 1.02   Grant   of   Security   Interest.    To  further  secure  the
Indebtedness, Mortgagor hereby grants to Mortgagee a security interest in and to
the Mortgaged Property (whether now or hereafter acquired by operation of law or
otherwise) insofar as the  Mortgaged  Property  consists of equipment, accounts,
contract rights, general intangibles, insurance contracts,  insurance  proceeds,
inventory, Hydrocarbons, fixtures and any and all other personal property of any
kind or character defined in and subject to the provisions of the Texas Business
and  Commerce  Code,  Chapters  1  through 9, as presently in effect (the "Texas
UCC"), including the proceeds and  products  from  any  and all of such personal
property.  Upon the happening of any of the Events of Default, Mortgagee is  and
shall  be  entitled to all of the rights, powers and remedies afforded a secured
party by the Texas UCC with  reference  to the personal property and fixtures in
which Mortgagee has been granted a security interest herein, or the  Trustee  or
Mortgagee  may  proceed as to both the real and personal property covered hereby
in accordance with  the  rights  and  remedies  granted  under  this Mortgage in
respect of the real property covered hereby.  Such rights, powers  and  remedies
shall be cumulative and in addition to those granted to the Trustee or Mortgagee
under  any  other  provision  of  this  Mortgage  or  under  any  other Security
Instrument.  Written notice  mailed  to  Mortgagor  as  provided herein at least
fifteen (15) days prior to the date of public sale of any part of the  Mortgaged
Property  which is personal property subject to the provisions of the Texas UCC,
or prior to the date after which private  sale of any such part of the Mortgaged
Property will be made, shall constitute reasonable notice.

    Section 1.03   Indebtedness  Secured.   This  Mortgage   is   executed   and
delivered by Mortgagor to secure and enforce the following (the "Indebtedness"):

    (a)  The payment of and performance of any and all indebtedness, obligations
and  liabilities  of  Mortgagor  pursuant  to  that certain Amended and Restated
Guaranty Agreement  of  even  date  herewith  executed  by  the Mortgagor, among
others, in favor of the Mortgagee (as the same may from time to time be amended,
supplemented or otherwise modified, the "Guaranty Agreement"), guaranteeing  the
prompt  and  complete  payment  when  due  (whether  at  the stated maturity, by
acceleration or  otherwise)  of  the  Obligations  (as  defined  in the Guaranty
Agreement) including, without limitation, the Letter of  Credit  and  the  Notes
with final maturity

                                      -4-

on or before April 30, 2000  and  any  obligations  arising  under  the  Hedging
Agreements with any Lender or its Affiliates.

    (b)  Any sums which may be advanced or paid by Mortgagee or any Lender under
the  terms  hereof  on  account  of  the failure of Mortgagor to comply with the
covenants of the Mortgagor contained herein  or in the Credit Agreement; and all
other indebtedness of Mortgagor arising  pursuant  to  the  provisions  of  this
Mortgage.

    Section 1.04   Fixture  Filing,  Etc.  Without  in  any  manner limiting the
generality of any of the other  provisions  of this Mortgage:  (i) some portions
of the goods described or to which reference is made herein are or are to become
fixtures on the land described or to  which  reference  is  made  herein  or  on
attached  Exhibit A; (ii) the security interests created hereby under applicable
provisions of the Texas UCC will  attach to Hydrocarbons (minerals including oil
and gas) or the accounts resulting from the sale  thereof  at  the  wellhead  or
minehead  located  on  the  land described or to which reference is made herein;
(iii) this Mortgage is to be  filed  of  record  in the real estate records as a
financing statement, and (iv) Mortgagor is the record owner of the  real  estate
or interests in the real estate comprised of the Mortgaged Property.

    Section 1.05   Defined  Terms.   Any  capitalized term used in this Mortgage
and not defined in this Mortgage shall have the meaning assigned to such term in
the Credit Agreement.

                                   ARTICLE II

                            Assignment of Production

    Section 2.01   Assignment.   Mortgagor  has  absolutely  and unconditionally
assigned,  transferred,  and  conveyed,   and   does   hereby   absolutely   and
unconditionally  assign,  transfer and convey unto Mortgagee, its successors and
assigns,  all  of  the  Hydrocarbons  and  all  products  obtained  or processed
therefrom, and the revenues and proceeds now and hereafter attributable  to  the
Hydrocarbons and said products and all payments in lieu of the Hydrocarbons such
as  "take or pay" payments or settlements.  The Hydrocarbons and products are to
be delivered into pipe lines  connected  with  the Mortgaged Property, or to the
purchaser thereof, to the credit of Mortgagee, free  and  clear  of  all  taxes,
charges,  costs,  and expenses; and all such revenues and proceeds shall be paid
directly to Mortgagee, at its banking  quarters in Houston, Harris County, Texas
with no duty or obligation of any party paying the  same  to  inquire  into  the
rights of Mortgagee to receive the same, what application is made thereof, or as
to  any other matter.  Mortgagor agrees to perform all such acts, and to execute
all  such  further  assignments,  transfers   and  division  orders,  and  other
instruments as may be required or desired by Mortgagee or any party in order  to
have  said  proceeds  and  revenues  so  paid  to Mortgagee.  Mortgagee is fully
authorized to receive and receipt for said revenues and proceeds; to endorse and
cash any and  all  checks  and  drafts  payable  to  the  order  of Mortgagor or
Mortgagee for the account of Mortgagor received from or in connection with  said
revenues  or  proceeds  and  to  hold  the proceeds thereof in a bank account as
additional collateral securing  the  Indebtedness;  and  to execute transfer and
division orders in the name of Mortgagor, or otherwise, with warranties

                                      -5-

binding  Mortgagor.   All  proceeds  received  by the Mortgagee pursuant to this
assignment shall be applied as  provided  in  the Credit Agreement, or after the
occurrence and during the continuance of an Event of Default, the Mortgagee  may
in  its  sole  discretion apply the proceeds as provided in Section 4.13 hereof.
Mortgagee shall not be  liable  for  any  delay,  neglect,  or failure to effect
collection of any proceeds or to take any other action in  connection  therewith
or  hereunder;  but Mortgagee shall have the right, at its election, in the name
of Mortgagor or otherwise, to prosecute and  defend any and all actions or legal
proceedings deemed advisable by Mortgagee in order to collect such funds and  to
protect  the  interests of Mortgagee, and/or Mortgagor, with all costs, expenses
and attorneys' fees incurred  in  connection  therewith being paid by Mortgagor.
Mortgagor hereby appoints Mortgagee as its attorney-in-fact to  pursue  any  and
all  rights  of Mortgagor to liens on and security interests in the Hydrocarbons
securing payment of  proceeds  of  runs  attributable  to  the Hydrocarbons.  In
addition to the rights granted to Trustee and/or Mortgagee in Section  1.01  (c)
of  this  Mortgage,  Mortgagor hereby further transfers and assigns to Mortgagee
any and all  such  liens,  security  interests,  financing statements or similar
interests of Mortgagor attributable to its  interest  in  the  Hydrocarbons  and
proceeds of runs therefrom arising under or created by said statutory provision,
judicial  decision  or otherwise.  The power of attorney granted to Mortgagee in
this paragraph, being coupled with an  interest, shall be irrevocable so long as
the Indebtedness or any part thereof remains unpaid.

    Section 2.02   Rights Under  Texas  Act.  Mortgagor  hereby  grants,  sells,
assigns,  sets  over and mortgages unto Mortgagee during the term hereof, all of
Mortgagor's rights and interests pursuant to  the provisions of  9.319 Tex. UCC,
hereby vesting in Mortgagee all of Mortgagor's rights as an  interest  owner  to
the continuing security interest in and lien upon the Mortgaged Property.

    Section 2.03   No  Modification  of  Payment  Obligations.   Nothing  herein
contained  shall  modify  or otherwise alter the obligation of Mortgagor to make
prompt payment of all principal and  interest owing on the Indebtedness when and
as the same become due regardless of whether the proceeds  of  the  Hydrocarbons
are  sufficient  to  pay the same and the rights provided in accordance with the
foregoing assignment provision shall be cumulative  of all other security of any
and every  character  now  or  hereafter  existing  to  secure  payment  of  the
Indebtedness.


                                  ARTICLE III

                   Representations, Warranties and Covenants

        Mortgagor hereby represents, warrants and covenants as follows:

    Section 3.01   Title.  To the extent of the undivided interests specified on
attached  Exhibit  A,  Mortgagor  has  good  and  indefeasible  title  to and is
possessed of the Mortgaged Property.  The  Mortgaged Property is free of any and
all Liens (as defined in the Credit Agreement) except Liens allowed  by  Section
5.04(b)  of  the  Credit  Agreement  and  Liens  described  on  Exhibit A hereto
(collectively, the "Permitted Encumbrances").

                                      -6-

    Section 3.02   Defend Title.  This Mortgage is,  and  always will be kept, a
direct first lien and security interest upon the Mortgaged Property subject only
to the Permitted Encumbrances and Mortgagor will not  create  or  suffer  to  be
created or permit to exist any lien, security interest or charge prior or junior
to  or on a parity with the lien and security interest of this Mortgage upon the
Mortgaged Property or any  part  thereof  or  upon  the rents, issues, revenues,
profits and other income therefrom.  Mortgagor will warrant and defend the title
to the Mortgaged Property against the claims and demands of  all  other  persons
whomsoever and will maintain and preserve the lien created hereby so long as any
of  the  Indebtedness secured hereby remains unpaid.  Should an adverse claim be
made against or a cloud  develop  upon  the  title  to any part of the Mortgaged
Property, Mortgagor agrees it will immediately defend against such adverse claim
or take appropriate action to remove such cloud at Mortgagor's cost and expense,
and Mortgagor further agrees that the Trustee and/or  Mortgagee  may  take  such
other  action  as they deem advisable to protect and preserve their interests in
the Mortgaged Property, and in  such  event Mortgagor will indemnify the Trustee
and Mortgagee against any and all cost, attorney's fees and other expenses which
they may incur in defending against any such adverse claim or taking  action  to
remove any such cloud.

    Section 3.03   Not  a  Foreign  Person.  Mortgagor is not a "foreign person"
within the meaning of the Internal Revenue Code of 1986, as amended (hereinafter
called  the  "Code"),  Sections  1445  and   7701  (i.e.   Mortgagor  is  not  a
non-resident alien, foreign corporation, foreign partnership, foreign  trust  or
foreign  estate  as  those  terms  are  defined  in the Code and any regulations
promulgated thereunder).

    Section 3.04   Power to Create Lien  and  Security.   The Mortgagor has full
power and lawful authority to grant, bargain, sell, assign, transfer,  mortgage,
and  convey  a  security interest in all of the Mortgaged Property in the manner
and form herein  provided  and  without  obtaining  the authorization, approval,
consent or waiver of any lessor,  sublessor,  Governmental  Authority  or  other
party or parties whomsoever.

    Section 3.05   Revenue  and Cost Bearing Interest.  Mortgagor's ownership of
the Hydrocarbon Property and  the  undivided  interests  therein as specified on
attached Exhibit A will, after giving full effect to all Permitted Encumbrances,
afford Mortgagor not less than those net interests in  the  production  from  or
which  is  allocated  to  such  Hydrocarbon  Property  specified as "Net Revenue
Interest" on attached Exhibit A (expressed as a fraction, percentage or decimal)
and will cause  Mortgagor  to  bear  not  more  than  that portion, specified as
"Working Interest" on attached Exhibit A (expressed as a fraction, percentage or
decimal),  of  the  costs  of  drilling,  developing  and  operating  the  wells
identified on Exhibit A.

    Section 3.06   Rentals Paid; Leases in Effect.  All  rentals  and  royalties
due  and  payable  in  accordance  with  the  terms  of  any leases or subleases
comprising a part of the  Hydrocarbon  Property  have been duly paid or provided
for and all leases or subleases comprising a part of  the  Hydrocarbon  Property
are in full force and effect.

                                      -7-

    Section 3.07   Operation  of  Mortgaged Property, Etc. Except as provided in
Section 3.08  Mortgagor  will  promptly  pay  and  discharge  all rentals, delay
rentals, royalties and indebtedness accruing under, and perform or cause  to  be
performed  each  and every act, matter or thing required by, each and all of the
assignments, deeds, leases,  sub-leases,  contracts  and agreements described or
referred to herein or affecting Mortgagor's interests in the Mortgaged Property,
and will do all other things necessary to  keep  unimpaired  Mortgagor's  rights
with  respect  thereto and prevent any forfeiture thereof or default thereunder.
The Mortgaged Property (and properties  unitized therewith) has been maintained,
operated and developed in a good and workmanlike manner and in  conformity  with
all  applicable  laws  and  all  rules,  regulations  and  orders  of  all  duly
constituted   authorities   having  jurisdiction  and  in  conformity  with  the
provisions of all leases, subleases or  other contracts comprising a part of the
Hydrocarbon Property and other contracts and agreements forming a  part  of  the
Mortgaged  Property;  specifically  in  this connection, (i) after the Effective
Date no Mortgaged Property  is  subject  to  having allowable production reduced
below  the  full  and  regular  allowable  (including  the  maximum  permissible
tolerance)  because  of  any  overproduction  (whether  or  not  the  same   was
permissible  at the time) prior to the Effective Date and (ii) none of the wells
comprising a part of the  Mortgaged  Property (or properties unitized therewith)
are deviated from the vertical more than the  maximum  permitted  by  applicable
laws, regulations, rules and orders, and such wells are, in fact, bottomed under
and  are  producing  from,  and  the well bores are wholly within, the Mortgaged
Property (or, in the  case  of  wells  located on properties unitized therewith,
such unitized properties).  Mortgagor will operate the Mortgaged Property  in  a
careful  and  efficient  manner in accordance with the practices of the industry
and in compliance with all applicable contracts and agreements and in compliance
with all applicable proration and conservation laws of the jurisdiction in which
the  Mortgaged  Property  is  situated,  and  all  applicable  laws,  rules  and
regulations of every other agency and authority from time to time constituted to
regulate the  development  and  operation  of  the  Mortgaged  Property  and the
production and sale of Hydrocarbons and  other  minerals  therefrom.   Mortgagor
will do or cause to be done such development work as may be reasonably necessary
to  the prudent and economical operation of the Mortgaged Property in accordance
with the most approved practices of  operators in the industry, including all to
be done that may be  appropriate  to  protect  from  diminution  the  productive
capacity  of  the  Mortgaged Property and each producing well thereon including,
without limitation, cleaning out and reconditioning each well from time to time,
plugging and  completing  at  a  different  level  each  such  well,  drilling a
substitute well to conform to changed spacing regulations  and  to  protect  the
Mortgaged Property against drainage whenever and as often as is necessary.

    Section 3.08   Operation By Third Parties.  All or portions of the Mortgaged
Property  may  be  comprised  of interests in the Hydrocarbon Property which are
other than working interests or  which  may  be  operated  by a party or parties
other than Mortgagor  and  with  respect  to  all  or  any  such  interests  and
properties  as  may  be  comprised  of interests other than working interests or
which may be operated by parties  other than Mortgagor, Mortgagor's covenants as
expressed in this Article III are modified to require  that  Mortgagor  use  its
best  efforts  to  obtain compliance with such covenants by the working interest
owners or the operator or operators of such leases or properties.

                                      -8-

    Section 3.09   Abandon, Sales.  The Mortgagor  will not sell, lease, assign,
transfer or otherwise dispose or abandon any of the Mortgaged Property except as
permitted by the Credit Agreement.

    Section 3.10   Failure  to  Perform.   The  Mortgagor  agrees  that  if  the
Mortgagor fails to perform any act or to take any action which the Mortgagor  is
required  to  perform  or take hereunder or pay any money which the Mortgagor is
required to  pay  hereunder,  each  of  the  Mortgagee  and  the  Trustee in the
Mortgagor's name or its or their own name may, but shall not  be  obligated  to,
perform  or cause to perform such act or take such action or pay such money, and
any expenses so incurred by either of  them  and  any money so paid by either of
them shall be a demand obligation owing by the Mortgagor to the Mortgagee or the
Trustee, as the case may be, and each of the Mortgagee  and  the  Trustee,  upon
making  such  payment,  shall  be  subrogated to all of the rights of the Person
receiving such payment.  Each amount due  and  owing by Mortgagor to each of the
Mortgagee and the Trustee pursuant to this Mortgage shall bear interest from the
date of such expenditure or payment or other occurrence which gives rise to such
amount being owed to such Person until paid at the rate  for  overdue  principal
and  interest  set  forth  in  Section  2.06(c)  of  the  Credit  Agreement (the
"Post-Default Rate"), and all such  amounts  together with such interest thereon
shall be a part of the Indebtedness described in Section 1.03 hereof.


                                   ARTICLE IV

                              Rights and Remedies

    Section 4.01   Event of Default.  An "Event of  Default"  under  the  Credit
Agreement shall be an Event of Default under this Mortgage.

    Section 4.02   Foreclosure and Sale.  If an Event of Default shall occur and
be  continuing  after  any applicable notice and cure period provided for in the
Credit Agreement, Mortgagee shall  have  the  right  and  option to proceed with
foreclosure by directing the Trustee, or his successors or substitutes in trust,
to proceed with foreclosure and to sell, to the extent permitted by law, all  or
any portion of the Mortgaged Property at one or more sales, as an entirety or in
parcels,  at  such place or places in otherwise such manner and upon such notice
as may be required by law, or,  in  the  absence of any such requirement, as the
Mortgagee may deem appropriate, and to  make  conveyance  to  the  purchaser  or
purchasers.   Where  the Mortgaged Property is situated in more than one county,
notice as above provided shall be posted and filed in all such counties (if such
notices are required by law), and all such Mortgaged Property may be sold in any
such county and any such notice  shall designate the county where such Mortgaged
Property is to be sold.   Nothing  contained  in  this  Section  4.02  shall  be
construed  so  as to limit in any way the Trustee's rights to sell the Mortgaged
Property, or any portion thereof, by  private  sale  if, and to the extent that,
such private sale is permitted under the laws of the applicable jurisdiction  or
by  public  or  private sale after entry of a judgment by any court of competent
jurisdiction so ordering.  Mortgagor hereby  irrevocably appoints the Trustee to
be the attorney

                                      -9-

of Mortgagor and in the name and on behalf of Mortgagor to execute  and  deliver
any  deeds,  transfers,  conveyances,  assignments, assurances and notices which
Mortgagor ought to execute and deliver and  do and perform any and all such acts
and things which Mortgagor ought to do and perform under  the  covenants  herein
contained  and generally, to use the name of Mortgagor in the exercise of all or
any of the powers  hereby  conferred  on  the  Trustee.   At any such sale:  (i)
whether made under the power herein contained or any other legal  enactment,  or
by  virtue  of  any  judicial  proceedings  or  any other legal right, remedy or
recourse, it shall not be necessary  for  Trustee to have physically present, or
to have constructive possession of, the  Mortgaged  Property  (Mortgagor  hereby
covenanting  and  agreeing  to  deliver  to Trustee any portion of the Mortgaged
Property not actually or  constructively  possessed  by Trustee immediately upon
demand by Trustee) and the title to and right of possession of any such property
shall pass to the purchaser thereof as  completely  as  if  the  same  had  been
actually  present  and delivered to purchaser at such sale, (ii) each instrument
of conveyance executed by  Trustee  shall  contain  a general warranty of title,
binding upon Mortgagor and its successors and  assigns,  (iii)  each  and  every
recital  contained  in  any  instrument  of  convey-  ance made by Trustee shall
conclusively establish the truth  and  accuracy  of the matters recited therein,
including, without limitation, nonpayment of the Indebtedness, advertisement and
conduct of such sale in the manner provided herein  and  otherwise  by  law  and
appointment  of  any successor Trustee hereunder, (iv) any and all prerequisites
to the validity thereof shall be con- clusively presumed to have been performed,
(v) the receipt of Trustee or  of  such  other  party or officer making the sale
shall be a sufficient discharge to the purchaser or purchasers for its  purchase
money  and  no  such  purchaser  or  purchasers,  or  its  assigns  or  personal
representatives, shall thereafter be obligated to see to the application of such
purchase  money,  or  be  in  any way answerable for any loss, misapplication or
nonapplication thereof, (vi) to the  fullest  extent permitted by law, Mortgagor
shall be completely and  irrevocably  divested  of  all  of  its  right,  title,
interest, claim and demand whatsoever, either at law or in equity, in and to the
property  sold  and such sale shall be a perpetual bar both at law and in equity
against Mortgagor, and against any  and  all  other persons claiming or to claim
the property sold or any part thereof, by, through or under Mortgagor, and (vii)
to the extent and under such circumstances as are permitted  by  law,  Mortgagee
may  be  a purchaser at any such sale, and shall have the right, after paying or
accounting for all costs of said sale or  sales, to credit the amount of the bid
upon the amount of the Indebtedness (in the  order  of  priority  set  forth  in
Section 4.13 hereof) in lieu of cash payment.

    Section 4.03   Substitute Trustees and Agents.  The Trustee or his successor
or  substitute  may  appoint  or  delegate  any  one or more persons as agent to
perform any act or  acts  necessary  or  incident  to  any sale held by Trustee,
including the posting of notices and the conduct of sale, but in the name and on
behalf of Trustee, his successor or substitute.  If Trustee or his successor  or
substitute  shall  have  given  notice  of  sale  hereunder,  any  successor  or
substitute trustee thereafter appointed may complete the sale and the conveyance
of  the  property  pursuant  thereto  as  if  such  notice had been given by the
successor or substitute trustee conducting the sale.

    Section 4.04   Judicial   Foreclosure;   Receivership.    If   any   of  the
Indebtedness shall become due and payable and shall not be  promptly  paid,  the
Trustee  or  Mortgagee  shall  have  the right and power to proceed by a suit or
suits in equity or at law, whether for the specific

                                      -10-

performance of any covenant  or  agreement  herein  contained  or  in aid of the
execution of any power herein granted, or for any foreclosure hereunder  or  for
the  sale of the Mortgaged Property under the judgment or decree of any court or
courts of competent jurisdiction, or  for  the appointment of a receiver pending
any foreclosure hereunder or the sale of the Mortgaged Property under the  order
of a court or courts of competent jurisdiction or under executory or other legal
process,  or  for  the  enforcement  of any other appropriate legal or equitable
remedy.  Any money advanced by  the  Trustee and/or Mortgagee in connection with
any such receivership shall be a demand obligation (which  obligation  Mortgagor
hereby  expressly  promises  to  pay)  owing  by Mortgagor to the Trustee and/or
Mortgagee and shall bear interest from  the  date  of making such advance by the
Trustee and/or Mortgagee until paid at the Post Default Rate.

    Section 4.05   Foreclosure for Installments.  Mortgagee shall also have  the
option  to  proceed  with foreclosure in satisfaction of any installments of the
Indebtedness which have not been paid  when  due either through the courts or by
directing the Trustee or his successors in trust to proceed with foreclosure  in
satisfaction of the matured but unpaid portion of the Indebtedness as if under a
full  foreclosure,  conducting the sale as herein provided and without declaring
the entire principal balance and  accrued  interest  due;  such sale may be made
subject to the unmatured portion of the Indebtedness, and any  such  sale  shall
not  in  any  manner affect the unmatured portion of the Indebtedness, but as to
such unmatured portion of the  Indebtedness  this  Mortgage shall remain in full
force and effect just as though no sale had been made hereunder.  It is  further
agreed  that several sales may be made hereunder without exhausting the right of
sale for any unmatured part of the  Indebtedness, it being the purpose hereof to
provide for a foreclosure and sale of the security for any  matured  portion  of
the  Indebtedness  without  exhausting  the  power  to  foreclose  and  sell the
Mortgaged Property for any subsequently maturing portion of the Indebtedness.

    Section 4.06   Separate Sales The Mortgaged Property  may  be sold in one or
more parcels and in such manner and order as Mortgagee, in its sole  discretion,
may  elect,  it  being  expressly  understood  and agreed that the right of sale
arising out of any Event of Default  shall  not  be exhausted by any one or more
sales.

    Section 4.07   Possession of Mortgaged Property.  Mortgagor  agrees  to  the
full  extent  that  it  lawfully may, that, in case one or more of the Events of
Default shall have occurred and shall not have been remedied, then, and in every
such case, the Trustee or Mortgagee shall have the right and power to enter into
and upon and take possession of all or any part of the Mortgaged Property in the
possession of Mortgagor, its successors  or  assigns,  or its or their agents or
servants, and may exclude Mortgagor, its successors or assigns, and all  persons
claiming  under  Mortgagor, and its or their agents or servants wholly or partly
therefrom; and, holding  the  same,  the  Trustee  may  use, administer, manage,
operate and control the Mortgaged Property and conduct the business  thereof  to
the  same  extent  as Mortgagor, its successors or assigns, might at the time do
and may exercise all rights  and  powers  of  Mortgagor,  in the name, place and
stead of Mortgagor, or otherwise as the Trustee shall  deem  best.   All  costs,
expenses  and  liabilities  of  every  character  incurred by the Trustee and/or
Mortgagee in administering, managing,  operating,  and controlling the Mortgaged
Property shall constitute a demand obligation (which obligation

                                      -11-

Mortgagor hereby expressly promises to pay) owing by Mortgagor  to  the  Trustee
and/or  Mortgagee and shall bear interest from date of expenditure until paid at
the  Post  Default  Rate,  all  of  which  shall  constitute  a  portion  of the
Indebtedness and shall be secured  by  this  Mortgage  and  all  other  Security
Instruments.

    Section 4.08   Occupancy  After  Foreclosure.   In  the  event  there  is  a
foreclosure sale hereunder and at the time of such sale Mortgagor or Mortgagor's
heirs,  devisees,  representatives,  successors  or  assigns or any other person
claiming any interest in the Mortgaged  Property by, through or under Mortgagor,
are occupying or using the Mortgaged Property or any part thereof, each and  all
shall immediately become the tenant of the purchaser at such sale, which tenancy
shall  be  a  tenancy  from  day  to  day,  terminable at the will of either the
landlord or tenant, or at a  reasonable  rental  per day based upon the value of
the property occupied, such rental to be due daily  to  the  purchaser;  to  the
extent   permitted  by  applicable  law,  the  purchaser  at  such  sale  shall,
notwithstanding any language herein  apparently  to  the contrary, have the sole
option to demand immediate possession  following  the  sale  or  to  permit  the
occupants  to  remain  as  tenants  at  will.   In the event the tenant fails to
surrender possession  of  said  property  upon  demand,  the  purchaser shall be
entitled to institute and maintain  a  summary  action  for  possession  of  the
Mortgaged  Property  (such  as an action for forcible entry and detainer) in any
court having jurisdiction.

    Section 4.09   Remedies  Cumulative,  Concurrent  and  Nonexclusive.   Every
right, power and  remedy  herein  given  to  the  Trustee  or Mortgagee shall be
cumulative and in addition  to  every  other  right,  power  and  remedy  herein
specifically  given or now or hereafter existing in equity, at law or by statute
(including specifically those granted  by  the  Texas  UCC and applicable to the
Mortgage Property or any portion thereof) each and every right, power and remedy
whether specifically herein given or otherwise existing may  be  exercised  from
time  to  time  and so often and in such order as may be deemed expedient by the
Trustee or Mortgagee, and the exercise, or the beginning of the exercise, of any
such right, power or  remedy  shall  not  be  deemed  a  waiver  of the right to
exercise, at the same time or thereafter any other right, power or  remedy.   No
delay  or  omission  by  the  Trustee or Mortgagee in the exercise of any right,
power or remedy shall impair any  such  right,  power  or remedy or operate as a
waiver thereof or of any  other  right,  power  or  remedy  then  or  thereafter
existing.

    Section 4.10   No  Release of Obligations.  Neither Mortgagor, any guarantor
nor any other person hereafter obligated for  payment  of all or any part of the
Indebtedness shall be relieved of such obligation by reason of (a)  the  failure
of  Trustee  to  comply  with  any request of Mortgagor, or any guarantor or any
other person so obligated to foreclose  the  lien of this Mortgage or to enforce
any provision  hereunder  or  under  the  Credit  Agreement;  (b)  the  release,
regardless of consideration, of the Mortgaged Property or any portion thereof or
interest  therein  or  the  addition  of  any  other  property  to the Mortgaged
Property; (c) any agreement or  stipulation  between any subsequent owner of the
Mortgaged Property and Mortgagee extending,  renewing,  rearranging  or  in  any
other way modifying the terms of this Mortgage without first having obtained the
consent  of,  given  notice  to  or  paid  any  consideration  to Mortgagor, any
guarantor or such other person, and  in  such event Mortgagor, guarantor and all
such other persons shall continue to be liable to make payment according to  the
terms of any such extension or

                                      -12-

modification  agreement  unless  expressly released and discharged in writing by
Mortgagee; or (d) by any other  act  or  occurrence save and except the complete
payment of the Indebtedness and the  complete  fulfillment  of  all  obligations
hereunder or under the Credit Agreement.

    Section 4.11   Release  of and Resort to Collateral.  Mortgagee may release,
regardless of consideration, any part  of  the Mortgaged Property without, as to
the remainder, in any way impairing, affecting, subordinating or  releasing  the
lien  or  security  interest  created  in  or  evidenced by this Mortgage or its
stature as a first and prior lien  and security interest in and to the Mortgaged
Property, and without in any way releasing or diminishing the liability  of  any
person  or  entity liable for the repayment of the Indebtedness.  For payment of
the Indebtedness, Mortgagee may resort  to  any  other security therefor held by
Mortgagee or Trustee in such order and manner as Mortgagee may elect.

    Section 4.12   Waiver of Redemption, Notice and Marshalling of Assets,  Etc.
To  the  fullest  extent  permitted  by  law,  Mortgagor  hereby irrevocably and
unconditionally waives  and  releases  (a)  all  benefits  that  might accrue to
Mortgagor by virtue of any  present  or  future  moratorium  law  or  other  law
exempting  the  Mortgaged Property from attachment, levy or sale on execution or
providing for any  appraisement,  valuation,  stay  of execution, exemption from
civil process, redemption or extension  of  time  for  payment;  (b)  except  as
provided  in  the  Credit  Agreement,  all notices of any Event of Default or of
Mortgagee's intention to accelerate maturity of the Indebtedness or of Trustee's
election to exercise or his  actual  exercise  of  any right, remedy or recourse
provided for hereunder or under the Credit Agreement; and (c)  any  right  to  a
marshalling  of  assets  or  a  sale in inverse order of alienation.  If any law
referred to in  this  Mortgage  and  now  in  force,  of  which Mortgagor or its
successor or successors might take  advantage  despite  the  provisions  hereof,
shall  hereafter  be repealed or cease to be in force, such law shall thereafter
be deemed not to constitute  any  part  of  the  contract herein contained or to
preclude the operation or application of the provisions hereof.

    Section 4.13   Discontinuance of Proceedings In case  Mortgagee  shall  have
proceeded  to  invoke any right, remedy or recourse permitted hereunder or under
the Credit Agreement and shall  thereafter  elect to discontinue or abandon same
for any reason, Mortgagee shall have the unqualified right so to do and, in such
an event, Mortgagor and Mortgagee shall be restored to  their  former  positions
with  respect  to  the  Indebtedness  this  Mortgage,  the Credit Agreement, the
Mortgaged Property and otherwise, and the rights, remedies, recourses and powers
of Mortgagee shall continue as if same had never been invoked.

    Section 4.14   Application of Proceeds.   The  proceeds  of  any sale of the
Mortgaged Property or any part thereof and all  other  monies  received  by  the
Trustee in any proceedings for the enforcement hereof, whose application has not
elsewhere herein been specifically provided for, shall be applied:

    (a)  first, to the  payment  of  all  expenses  incurred  by  the Trustee or
Mortgagee incident to the enforcement of this Mortgage, the Credit Agreement  or
any  of  the  Indebtedness  (including,  without  limiting the generality of the
foregoing, expenses of any entry or taking of

                                      -13-

possession, of any sale, of advertisement thereof, and of conveyances, and court
costs, compensation of agents and employees, and legal fees), and to the payment
of all other charges, expenses, liabilities and advances incurred or made by the
Trustee or Mortgagee under  this  Mortgage  or  in  executing any trust or power
hereunder;

    (b)  second to payment of the Indebtedness  in  such  order  and  manner  as
Mortgagee may elect; and

    (c)  third,  to  Mortgagor;  or  as  otherwise  required by any Governmental
Requirement.

    Section 4.15   Resignation of  Operator.   In  addition  to  all  rights and
remedies under this Mortgage, at law and in equity,  if  any  Event  of  Default
shall  occur and Trustee or the Mortgagee shall exercise any remedies under this
Mortgage with respect to  any  portion  of  the Mortgaged Property (or Mortgagor
shall transfer any Mortgaged Property "in lieu of" foreclosure),  the  Mortgagee
or  the  Trustee  shall  have  the  right  to  request  that any operator of any
Mortgaged Property, to  the  extent  such  operator  is  either Mortgagor or any
Affiliate of Mortgagor, resign as operator under the joint  operating  agreement
applicable  thereto, and no later than 60 days after receipt by Mortgagor of any
such request, Mortgagor shall resign  (or  cause  such other party to resign) as
operator of such Mortgaged Property.

    Section 4.16   Indemnity.  In  connection  with  any  action  taken  by  the
Trustee and/or Mortgagee pursuant to this Mortgage, the Trustee and/or Mortgagee
and  their  officers,  directors, employees, representatives, agents, attorneys,
accountants and experts ("Indemnified Parties") shall not be liable for any loss
sustained by Mortgagor resulting from  an  assertion that Mortgagee has received
funds from the production of Hydrocarbons claimed by third persons or any act or
omission of any Indemnified  Party  in  administering,  managing,  operating  or
controlling the Mortgaged Property including such loss which may result from the
ordinary  negligence  of  an Indemnified Party unless such loss is caused by the
willful misconduct or bad faith of  an  Indemnified Party, nor shall the Trustee
and/or Mortgagee be obligated to perform or discharge any  obligation,  duty  or
liability of Mortgagor.  Mortgagor shall and does hereby agree to indemnify each
Indemnified Party for, and to hold each Indemnified Party harmless from, any and
all  liability, loss or damage which may or might be incurred by any Indemnified
Party by  reason  of  this  Mortgage  or  the  exercise  of  rights  or remedies
hereunder; should the Trustee and/or Mortgagee make any expenditure  on  account
of  any  such  liability,  loss  or damage, the amount thereof, including costs,
expenses and reasonable attorneys'  fees,  shall  be  a demand obligation (which
obligation Mortgagor hereby expressly promises to pay) owing by Mortgagor to the
Trustee and/or Mortgagee and shall bear interest from the  date  expended  until
paid  at the Post-Default Rate, shall be a part of the Indebtedness and shall be
secured by this Mortgage and any  other Security Instrument.  The liabilities of
the

                                      -14-

Mortgagor as set forth in this Section 4.15 shall  survive  the  termination  of
this Mortgage.


                                   ARTICLE V

                                  The Trustee

    Section 5.01   Duties,  Rights,  and Powers of Trustee.  It shall be no part
of the duty of the Trustee  to  see  to any recording, filing or registration of
this Mortgage or any other instrument in addition or supplemental thereto, or to
give any notice thereof, or to see to the payment of or be  under  any  duty  in
respect  of  any  tax  or  assessment  or other governmental charge which may be
levied or assessed on the  Mortgaged  Property,  or any part thereof, or against
Mortgagor, or to see to the performance or observance by Mortgagor of any of the
covenants and agreements contained herein.  The Trustee shall not be responsible
for the execution, acknowledgment  or  validity  of  this  Mortgage  or  of  any
instrument  in  addition  or  supplemental  hereto or for the sufficiency of the
security purported to be created hereby,  and makes no representation in respect
thereof or in respect of the rights of Mortgagee.  The Trustee  shall  have  the
right  to  advise  with  counsel upon any matters arising hereunder and shall be
fully protected in relying as to  legal  matters  on the advice of counsel.  The
Trustee shall not incur any personal liability hereunder  except  for  Trustee's
own  willful  misconduct;  and  the  Trustee shall have the right to rely on any
instrument, document or signature authorizing  or supporting any action taken or
proposed to be taken by him hereunder, believed by  him  in  good  faith  to  be
genuine.

    Section 5.02   Successor  Trustee.  The Trustee may resign by written notice
addressed to Mortgagee or be removed  at  any  time  with or without cause by an
instrument in writing duly executed on behalf of  Mortgagee.   In  case  of  the
death,  resignation  or  removal  of  the  Trustee,  a  successor trustee may be
appointed  by  Mortgagee  by  instrument  of  substitution  complying  with  any
applicable requirements of law,  or,  in  the  absence  of any such requirement,
without other formality than appointment and designation  in  writing.   Written
notice  of  such  appointment  and  designation  shall  be given by Mortgagee to
Mortgagor, but the validity of  any  such  appointment  shall not be impaired or
affected by failure to  give  such  notice  or  by  any  defect  therein.   Such
appointment and designation shall be full evidence of the right and authority to
make  the same and of all the facts therein recited, and, upon the making of any
such appointment and  designation,  this  Mortgage  shall  vest in the successor
trustee all the estate and title in and to all of the  Mortgaged  Property,  and
the  successor  trustee  shall  thereupon  succeed to all of the rights, powers,
privileges, immunities  and  duties  hereby  conferred  upon  the  Trustee named
herein, and one such appointment and designation shall not exhaust the right  to
appoint  and  designate  a  successor  trustee  hereunder  but such right may be
exercised repeatedly as long as  any  Indebtedness remains unpaid hereunder.  To
facilitate the administration of the duties  hereunder,  Mortgagee  may  appoint
multiple  trustees  to  serve  in  such  capacity  or  in  such jurisdictions as
Mortgagee may designate.

                                      -15-

    Section 5.03   Retention of Moneys.  All  moneys  received by Trustee shall,
until used or applied as herein provided, be held in trust for the purposes  for
which  they  were  received,  but  need not be segregated in any manner from any
other moneys (except to the extent required  by law), and Trustee shall be under
no liability for interest on any moneys received by him hereunder.


                                   ARTICLE VI

                                 Miscellaneous

    Section 6.01   Instrument Construed as Mortgage, Etc. With  respect  to  any
portions  of  the  Mortgaged Property located in any state or other jurisdiction
the laws of which do not provide for  the  use or enforcement of a deed of trust
or the office, rights and authority of  the  Trustee  as  herein  provided,  the
general  language  of  conveyance hereof to the Trustee is intended and the same
shall be construed as words of mortgage  unto  and in favor of Mortgagee and the
rights and authority granted to the Trustee herein may be enforced and  asserted
by  Mortgagee  in  accordance  with  the  laws of the jurisdiction in which such
portion of the Mortgaged Property is  located  and the same may be foreclosed at
the option of Mortgagee as to any or all such portions of the Mortgaged Property
in any manner permitted by the laws of the jurisdiction in which  such  portions
of  the  Mortgaged  Property  is  situated.  This Mortgage may be construed as a
mortgage, deed  of  trust,  chattel  mortgage,  conveyance, assignment, security
agreement, pledge, financing statement, hypothecation or contract, or any one or
more of them, in order fully to effectuate the lien hereof and the purposes  and
agreements herein set forth.

    Section 6.02   Release  of  Mortgage.   If  all  Indebtedness secured hereby
shall be paid and  the  Credit  Agreement  terminated, Mortgagee shall forthwith
cause satisfaction and discharge of this Mortgage to be entered upon the  record
at  the  expense  of  Mortgagor  and  shall  execute  and deliver or cause to be
executed and delivered such instruments  of satisfaction and reassignment as may
be appropriate.  Otherwise, this Mortgage shall  remain  and  continue  in  full
force and effect.

    Section 6.03   Severability.    If   any  provision  hereof  is  invalid  or
unenforceable in any jurisdiction, the  other  provisions hereof shall remain in
full force and effect in such jurisdiction and the remaining  provisions  hereof
shall  be  liberally construed in favor of the Trustee and Mortgagee in order to
effectuate the provisions hereof, and  the invalidity or unenforceability of any
provision  hereof  in  any  jurisdiction  shall  not  affect  the  validity   or
enforceability of any such provision in any other jurisdiction.

    Section 6.04   Successors  and  Assigns of Parties.  The term "Mortgagee" as
used herein shall mean and include  any legal owner, holder, assignee or pledgee
of any of the Indebtedness secured hereby.  The terms used to designate Trustee,
Mortgagee and Mortgagor shall be deemed to include the respective  heirs,  legal
representatives, successors and assigns of such parties.

                                      -16-

    Section 6.05   Satisfaction  of  Prior  Encumbrance.   To  the  extent  that
proceeds  of  the  Credit  Agreement are used to pay indebtedness secured by any
outstanding lien, security  interest,  charge  or  prior encumbrance against the
Mortgaged Property, such proceeds have been advanced by Mortgagee at Mortgagor's
request, and Mortgagee shall be subrogated  to  any  and  all  rights,  security
interests  and  liens  owned  by  any owner or holder of such outstanding liens,
security interests, charges or encumbrances, irrespective of whether said liens,
security interests, charges or  encumbrances  are  released, and it is expressly
understood that, in consideration of the payment of such other  indebtedness  by
Mortgagee, Mortgagor hereby waives and releases all demands and causes of action
for offsets and payments to, upon and in connection with the said indebtedness.

    Section 6.06   Subrogation  of  Trustee.   This  Mortgage  is made with full
substitution and subrogation of the Trustee and his successors in this trust and
his and  their  assigns  in  and  to  all  covenants  and  warranties  by others
heretofore given or made in respect  of  the  Mortgaged  Property  or  any  part
thereof.

    Section 6.07   Nature  of  Covenants.   The  covenants and agreements herein
contained shall constitute covenants running with the land and interests covered
or affected hereby and shall  be  binding upon the heirs, legal representatives,
successors and assigns of the parties hereto.

    Section 6.08   Notices.  All notices, requests, consents, demands and  other
communications  required or permitted hereunder shall be in writing and shall be
deemed sufficiently given or furnished  if  delivered by registered or certified
United States mail, postage prepaid, or by personal service  (including  express
or  courier  service)  at  the  addresses  specified at the end of this Mortgage
(unless changed by similar notice in writing given by the particular party whose
address is to be changed).  Any such  notice or communication shall be deemed to
have been given either at the time of personal  delivery  or,  in  the  case  of
delivery  at  the  address  and  in  the  manner  provided herein, upon receipt;
provided that, service of notice as required  by  the laws of any state in which
portions of the Mortgaged Property may be situated shall  for  all  purposes  be
deemed appropriate and sufficient with the giving of such notice.

    Section 6.09   Counterparts.   This  Mortgage  is  being executed in several
counterparts, all of which are identical, except that to facilitate recordation,
if the Mortgaged  Property  is  situated  in  more  than  one county, only those
portions of the description of the Mortgaged Property attached hereto as Exhibit
A located in the county in which a particular counterpart is recorded  shall  be
attached  hereto.   A  complete  Exhibit  A  will  be  attached  to that certain
counterpart to be attached to a Financing Statement and filed with the Secretary
of State  of  Texas  in  the  Uniform  Commercial  Code  Records.   Each of such
counterparts shall for all purposes be deemed to be an  original  and  all  such
counterparts shall together constitute but one and the same instrument.

    Section 6.10   Exculpation   Provisions.    Each   of   the  parties  hereto
specifically agrees that it has a duty to read this Mortgage; and agrees that it
is charged with notice and knowledge of the terms of this Mortgage; that it

                                      -17-

has in fact read this Mortgage  and  is  fully  informed and has full notice and
knowledge of the terms, conditions and effects of this  Mortgage;  that  it  has
been  represented  by  legal  counsel  of its choice throughout the negotiations
preceding its execution of this  Mortgage;  and  has  received the advice of its
attorney in entering into this Mortgage; and that it recognizes that certain  of
the  terms  of this Mortgage result in one party assuming the liability inherent
in some  aspects  of  the  transaction  and  relieving  the  other  party of its
responsibility for such liability.  Each party hereto agrees and covenants  that
it  will not contest the validity or enforceability of any exculpatory provision
of this Mortgage on the basis that the  party had no notice or knowledge of such
provision or that the provision is not "conspicuous."

                   [SIGNATURE BEGINS NEXT PAGE]

                                      -18-

    WITNESS THE EXECUTION HEREOF, this 7th day of June, 1996, to be effective as
of the 7th day of June, 1996 (the "Effective Date").


                                  MORTGAGOR:

                                  TESORO E&P COMPANY, L.P.

                                  By:  Tesoro Exploration and Production
                                       Company, its general partner



                                  By: /s/ G. A. Wright
                                  Name:     G. A. Wright
                                  Title:    Vice President and Treasurer




The name and address of the Debtor/Mortgagor is:

    TESORO E&P COMPANY, L.P.
    8700 Tesoro Drive
    San Antonio, Texas  78217

The name and address of the Secured Party/Mortgagee is:

    BANQUE PARIBAS, AS ADMINISTRATIVE AGENT
    1200 Smith Street, Suite 3100
    Houston, Texas  77002

                                      -19-

THE STATE OF TEXAS

COUNTY  OF  HARRIS


    THIS INSTRUMENT was acknowledged before me  on  June  7th,  1996  by  G.  A.
Wright,  Vice  President  and  Treasurer  of  Tesoro  Exploration and Production
Company, a Delaware corporation, general partner  of Tesoro E&P Company, L.P., a
Delaware limited liability company, on behalf of such corporation.



                                  /s/ Linda Daugherty
                                  Notary Public in and for the
                                  State of TEXAS

                                      -20-