EXHIBIT 10.51

                            KENNECOTT URANIUM COMPANY
                                    Mortgagor

                                       and

                            KENNECOTT ENERGY COMPANY
                                    Mortgagee
                         ------------------------------

                                    MORTGAGE,
                               SECURITY AGREEMENT,
                             FINANCING STATEMENT AND
                             ASSIGNMENT OF PROCEEDS,
                                RENTS AND LEASES
                         ------------------------------

                            Dated as of June 23, 1997

This  instrument  affects  real and personal  property  situated in the State of
Wyoming, in Fremont and Sweetwater Counties.

A carbon, photographic or other reproduction of this instrument is sufficient as
a  financing  statement.   This  instrument  contains   after-acquired  property
provisions.  This instrument  secures  payment of obligations  undertaken by the
Mortgagor  in a principal  amount of  U.S.$16,000,000,  together  with  interest
thereon.  This instrument covers proceeds of collateral.  This instrument covers
minerals and other substances of value which may be extracted from the earth and
which will be financed at the mine portal of the mines located on the properties
described  in  Exhibit A hereto.  This  financing  statement  is to be filed for
record  in the  real  estate  records  of the  county  records  of  Fremont  and
Sweetwater  Counties.  Mortgagor  is the record  owner of the real estate as set
forth in Exhibit A attached  hereto.  The  Mortgagee is not a seller or purchase
money lender of the collateral covered by this financing statement.

For purposes of recording this  instrument as a financing  statement,  Kennecott
Uranium  Company  is the  Debtor and  Kennecott  Energy and Coal  Company is the
Secured Party.


        RECORD AND RETURN TO:

        Lawrence R. Barusch, Esq.
        Parsons Behle & Latimer
        201 South Main Street
        Suite 1800
        Salt Lake City, Utah  84111



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                                                                   EXHIBIT 10.51

                                TABLE OF CONTENTS
                                                                          PAGE
ARTICLE 1      GRANT OF SECURITY INTERESTS...................................1
        1.1    Grant of Security Interests...................................1
        1.2    Obligations Secured...........................................3
        1.3    Maturity......................................................3

ARTICLE 2      OWNERSHIP CONDITION, ETC. OF MORTGAGED PROPERTY...............4
        2.1    [Intentionally omitted].......................................4
        2.2    Recordation...................................................4
        2.3    Payment of Impositions, etc...................................4
        2.4    Maintenance of Existence......................................4
        2.5    Compliance with Laws; Permits.................................4
        2.6    Adverse Possession............................................5
        2.7    Records and Inspection........................................5
        2.8    Defense of Title..............................................5
        2.9    Liens.........................................................5
        2.10   Maintenance of Ownership of Property..........................5
        2.11   No Claims Against Mortgagee, etc..............................5
        2.12   Assignment of Rents...........................................6
        2.13   Acquired Property Subject to Lien.............................6

ARTICLE 3      INSURANCE: DAMAGE, DESTRUCTION OR TAKING, ETC.................7
        3.1    Insurance.....................................................7
        3.2    Damage, Destruction or Taking; Mortgagor to 
               Give Notice; Assignment of Awards.............................8
        3.3    Application of Proceeds.......................................9
        3.4    Total Taking and Total Destruction............................9
        3.5    Restoration..................................................10

ARTICLE 4      ENVIRONMENTAL INDEMNIFICATION................................10
        4.1    Indemnification..............................................10
        4.2    Inspection...................................................11
        4.3    Actions by Mortgagee.........................................11
        4.4    Intervention.................................................12
        4.5    Nonexclusivity...............................................12

ARTICLE 5      EVENTS OF DEFAULT; REMEDIES, ETC.............................12
        5.1    Events of Default; Declaration of Note Due...................12
        5.2    Legal Proceedings; Foreclosure; Rescission...................14
        5.3    Power of Sale................................................14
        5.4    Mortgagee Authorized to Execute Deeds, etc...................14
        5.5    Purchase of Mortgaged Property by Mortgagee .................15

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                                                                   EXHIBIT 10.51

        5.6    Receipt a Sufficient Discharge to Purchaser..................15
        5.7    Waiver of Appraisement, Valuation, etc.......................15
        5.8    Sale a Bar Against Mortgagor.................................15
        5.9    Note to Become Due on Sale...................................15
        5.10   Application of Proceeds of Sale and Other Moneys.............15
        5.11   Appointment of Receiver......................................16
        5.12   Possession, Management and Income............................16
        5.13   Right of Mortgagee to Perform Mortgagor's Covenants, etc.....17
        5.14   Remedies, etc., Cumulative...................................17
        5.15   Attorneys' Fees etc..........................................17
        5.16   Provisions Subject to Applicable Law.........................17
        5.17   No Waiver, etc...............................................17
        5.18   Compromise of Actions, etc...................................18

ARTICLE 6      MISCELLANEOUS................................................18
        6.1    Further Assurances...........................................18
        6.2    Additional Security..........................................18
        6.3    Release, Partial Release, etc................................18
        6.4    Notices, etc.................................................18
        6.5    Amendments and Waivers.......................................19
        6.6    Expenses.....................................................19
        6.7    [Intentionally Omitted] .....................................19
        6.8    WAIVER OF JURY TRIAL.........................................20
        6.9    Miscellaneous................................................20


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                                                                   EXHIBIT 10.51

                          MORTGAGE, SECURITY AGREEMENT,
                             FINANCING STATEMENT AND
                    ASSIGNMENT OF PROCEEDS, RENTS AND LEASES

        THIS MORTGAGE, SECURITY AGREEMENT, FINANCING STATEMENT AND ASSIGNMENT OF
PROCEEDS,  RENTS AND LEASES is entered  into and is effective as of the 23rd day
of June, 1997, by and between KENNECOTT URANIUM COMPANY, a Delaware corporation
("Mortgagor"),   and   KENNECOTT   ENERGY   COMPANY,   a  Delaware   corporation
("Mortgagee").

        IN  CONSIDERATION of the matters herein set forth and for other good and
valuable  consideration,  the  receipt  and  sufficiency  of  which  are  hereby
acknowledged, Mortgagor hereby covenants and agrees as follows:

                                    ARTICLE 1

                           Grant of Security Interests

        1.1 GRANT OF SECURITY INTERESTS.  Mortgagor does hereby grant, mortgage,
pledge, assign, and convey to Mortgagee,  and to its successors and assigns, for
the  benefit  and  security  of  Mortgagee  under and  subject  to the terms and
conditions herein set forth, the following property (the "Mortgaged Property"):

          (a) All of Mortgagor's  present or hereafter acquired right, title and
interest in and to the following:

              (i)  the   patented   and   unpatented   federal   mining   claims
          (collectively, the "Mining Claims") described on Exhibit A,

              (ii)  the  patented  and  unpatented   federal   millsite   claims
          (collectively, the "Millsite Claims") described on Exhibit A,

              (iii) the  mining or other  leases  (collectively,  the  "Leases")
          described on Exhibit A hereto and made a part hereof, together with

              (iv) all other  unpatented  federal  mining  claims  and  millsite
          claims,  mining or other leases, fee simple estates,  surface estates,
          mineral estates,  royalty interests,  overriding royalty interests and
          net profit or other interests in real property  covering,  relating to
          or  affecting  property  located in Fremont and  Sweetwater  Counties,
          Wyoming,  constituting  Mortgagor's  interest  in the  Big  Eagle  and
          Jackpot  Mines  and  the  Sweetwater   Mill  located  in  Fremont  and
          Sweetwater Counties, Wyoming

(the Mining  Claims,  the Millsite  Claim,  the Leases  together with such other
property,  rights,  leases,  claims and interests being collectively  called the
"Claims"); including, without limitation,

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                                                                   EXHIBIT 10.51

all relocations of, amendments to and patents or land exchanges obtained in lieu
of the Mining  Claims and the  Millsite  Claims  (which shall be included in the
definition  of "Mining  Claims" or "Millsite  Claims",  as the case may be); all
amendments  to and  replacements  of the Leases  (which shall be included in the
definition of "Leases"): all veins, lodes and ledges and all of the dips, spurs,
angles,  pits, dumps, ponds,  tailings,  leach heaps, slag piles and stock piles
situate on the Claims or therein or  appurtenant  thereto;  together with all of
the other minerals,  ore, concentrate,  core bar and refined metals,  including,
without limitation all inventories of minerals,  warehouse receipts or documents
of title covering the same  (collectively,  the  "Minerals") in, on or under the
Claims (the Claims and the  Minerals  being  collectively  called the  "Lands");
together with all surface rights, easements, rights-of-way, and all other rights
of Mortgagor to use, mine,  remove and process the Minerals;  and all additional
lands, leases,  estates,  after-acquired titles, mining claims,  millsite claims
and access and  development  rights  hereafter  acquired by Mortgagor for use in
connection with the Lands;

          (b) All of Mortgagor's  present or hereafter acquired right, title and
interest in and to the following:  (i) (collectively,  the "Improvements"):  all
buildings, structures,  improvements and fixtures and any alterations thereto or
replacements  thereof, now or hereafter located in, on or under, affixed or made
appurtenant to or erected on the Lands, and (ii) (collectively, the "Easements")
all easements,  licenses,  privileges,  uses and  rights-of-way now or hereafter
appurtenant to the Lands or the Improvements or used in connection  therewith or
with the mining of the Minerals,  including,  without limitation,  the easements
and rights of way described on Exhibit B hereto;

          (c) All of Mortgagor's  present or hereafter acquired right, title and
interest in and to the following  (collectively,  the "Water Rights"): all water
and  water  rights,   together  with  all   applications  for  water  rights  or
applications or permits for the use,  transfer or change of water rights,  ditch
and ditch rights, well and well rights, reservoir and reservoir rights, stock or
interest in irrigation or ditch companies appurtenant to the Lands and all other
rights to water for use at or in connection with the Lands or the  Improvements,
or the mining of the  Minerals,  including,  without  limitation,  those  rights
listed on Exhibit C hereto;

          (d) All of Mortgagor's  present or hereafter acquired right, title and
interest in and to the following (collectively, the "Equipment"): the surface or
subsurface  machinery,  equipment,  motor  vehicles  and  other  rolling  stock,
facilities,  structures and fixtures (as defined in accordance  with  applicable
law), supplies, inventory, fittings, appliances,  apparatus, material, goods and
other  articles of personal  property or  replacements  thereof now or hereafter
located  in,  on  or  under,  affixed  to or  installed  on  the  Lands  or  the
Improvements  or used or  purchased  for use in  connection  with the  locating,
mining, production,  treatment, storage, transportation,  manufacture or sale of
the Minerals or the use or operation of the items listed above, the Lands or the
Improvements,  including,  without  limitation,  those items listed on Exhibit D
hereto;

          (e) All of Mortgagor's  present or hereafter acquired right, title and
interest in and to the following (collectively,  the "Agreements"):  (i) leases,
subleases,  agreements,  contracts,  instruments,  evidences  of title  (and any
claims or causes of action under or with respect to such

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                                                                   EXHIBIT 10.51

evidences of title), access,  operating,  joint venture, mining partnership,  or
other  agreements  relating  to the  development  or  operation  of  the  Lands,
including,  without limitation, the leases and agreements described on Exhibit E
hereto;  and (ii) all  permits,  bonds and  licenses,  and all other  documents,
accounts,  contract rights and general  intangibles now or hereafter arising out
of, used in  connection  with or relating to the locating,  mining,  production,
treatment, storage,  transportation,  manufacture or sale of the Minerals or the
use or operation of the Lands or the Improvements  (all to the extent a security
interest may be granted therein under the terms thereof and applicable law);

          (f) All  claims,  rights  and  causes of action in  contract,  tort or
otherwise  in any way  relating  to or  arising  out of the  acquisition  of the
Mortgaged Property by Mortgagor;

          (g)  All  accounts,   contract  rights,  rents,   revenues,   bonuses,
royalties, payments, profits, issues, incomes, products, documents, instruments,
inventories,  general intangibles,  accessions,  proceeds and other benefits, if
any,  arising from any of the Mortgaged  Property  described in  paragraphs  (a)
through (f) of this  section 1.1 (all to the extent a security  interest  may be
granted therein under the terms thereof and applicable law); and

          (h) All proceeds of the conversion,  voluntary or involuntary,  of any
of the  Mortgaged  Property  described  in  paragraphs  (a)  through (g) of this
section  1.1 into cash or  liquidated  claims,  including,  without  limitation,
proceeds of insurance and condemnation awards.

        Without limiting any of the other provisions of this Mortgage, Mortgagor
further expressly grants to Mortgagee,  as secured party, a security interest in
all of those  portions of the Mortgaged  Property which are or may be subject to
the  Wyoming  Uniform   Commercial   Code   provisions   applicable  to  secured
transactions.

        1.2 OBLIGATIONS  SECURED.  This Mortgage is executed,  acknowledged  and
delivered  by  Mortgagor to secure and enforce the  following  obligations  (the
"Obligations") of Mortgagor:

          (a) The  obligations  of Mortgagor to Mortgagee  under the  promissory
note,  dated  the 23rd day of June,  1997 in the  principal  amount  of  sixteen
million dollars  (U.S.$16,000,000),  (the "Note") together with interest thereon
at the rate and upon the terms provided in the Note;

          (b) The other  obligations  of  Mortgagor to Mortgagee to perform each
and  every  term,  covenant  and  condition  of  the  Note,  together  with  the
obligations  of Mortgagor to Mortgagee to perform each and every term,  covenant
and condition of this Mortgage;

          (c) All  indebtedness,  liabilities  and  obligations  of Mortgagor to
Mortgagee  arising  pursuant to this  Mortgage or the Note  (including,  without
limitation, all costs and expenses reasonably incurred by Mortgagee,  including,
without limitation, all legal, engineering and consulting fees, made and arising
pursuant  to  this  Mortgage  or the  Note or any  part  thereof,  any  renewal,
extension or change of or substitution for such obligations or any part thereof,
or

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                                                                   EXHIBIT 10.51

the acquisition or perfection of the security  therefor,  whether such advances,
costs and  expenses  were made and  incurred  at the  request  of  Mortgagor  or
Mortgagee); and

          (d)  All  renewals,   extensions,   amendments   and  changes  of,  or
substitutions  for, all or any part of the  Obligations  described in paragraphs
(a) through (c) of this section 1.2.

        1.3 MATURITY. The maturity date of the Note is June 23, 2010.

                                    ARTICLE 2

                 OWNERSHIP CONDITION, ETC. OF MORTGAGED PROPERTY

        2.1 [Intentionally omitted].

        2.2 RECORDATION. Mortgagor, at its expense, will at all times cause this
Mortgage and any instruments  amendatory  hereof or supplemental  hereto and any
instruments  of  assignment  hereof or thereof  (and any  appropriate  financing
statements or other  instruments and  continuations  thereof with respect to any
thereof)  to  be  recorded,  registered  and  filed  and  to be  kept  recorded,
registered and filed,  in such manner and in such places,  and will pay all such
recording,  registration,  filing fees and other charges, and will take all such
further action and will comply with all such statutes and  regulations as may be
required by law in order to establish, preserve, perfect and protect the lien of
this  Mortgage as a valid and direct  mortgage  lien on and  perfected  security
interest in the Mortgaged  Property of a priority at least equal to the priority
existing on the date hereof.  Mortgagor  will pay or cause to be paid,  and will
indemnify  Mortgagee in respect of, all taxes (including interest and penalties)
at any time payable in connection with the filing and recording of this Mortgage
and any and all supplements and amendments thereto.  Mortgagor,  at its expense,
will furnish to Mortgagee,  upon request,  but not more  frequently than once in
every twelve month  period,  an opinion of counsel  reasonably  satisfactory  to
Mortgagee,  specifying the action taken by Mortgagor to comply with this section
2.2  since the date of this  Mortgage  or the last such  request  hereunder,  or
stating that no such action is necessary.

        2.3 PAYMENT OF IMPOSITIONS,  ETC. Mortgagor also agrees that it will pay
or cause to be paid before the same would become delinquent and before any fine,
penalty, interest or cost may be added for non-payment,  all taxes, assessments,
charges,  and other  governmental  levies or payments,  of every kind and nature
whatsoever, general and special, ordinary and extraordinary,  unforeseen as well
as foreseen, which at any time may be assessed,  levied,  confirmed,  imposed or
which may become a lien upon the Mortgaged Property,  or any portion thereof, or
which are payable with respect  thereto,  or upon the rents,  issues,  income or
profits thereof, or on the occupancy,  operation,  use, possession or activities
thereof,  whether any or all of the same be levied  directly or indirectly or as
excise taxes or as income taxes (collectively, the "Impositions").

        2.4  MAINTENANCE OF EXISTENCE.  The Mortgagor will at all times preserve
and keep in full  force and  effect its  existence,  and  rights and  franchises
material to its business, and qualify

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                                                                   EXHIBIT 10.51

and  remain  qualified  as a  foreign  corporation  in  good  standing  in  each
jurisdiction  in which the  nature of its  activities  or the  character  of the
properties it owns or leases makes such qualification necessary and in which the
failure to so qualify would have a materially adverse effect on the Mortgagor.

        2.5  COMPLIANCE  WITH  LAWS;  PERMITS.  Mortgagor  shall  comply  in all
material  respects  with all  applicable  laws,  rules,  regulations  and orders
(including  without  limitation,  all  environmental  laws),  such compliance to
include, without limitation, paying before the same become delinquent, all taxes
imposed upon it or any of its  properties  or assets and obtain and keep in full
force and effect all required licenses, permits and approvals.

        2.6 ADVERSE POSSESSION.  Mortgagor shall take any and all such action as
may be  necessary  to prevent any third  parties  from  acquiring  any  material
prescriptive  easement upon, over, or across any part of the Mortgaged Property,
or from  acquiring any material  rights to or against the Mortgaged  Property by
virtue of adverse possession.

        2.7 RECORDS AND INSPECTION.  Mortgagor  shall keep adequate  records and
books of account,  in which  complete  entries will be made in  accordance  with
generally accepted accounting principals  consistently  applied,  reflecting all
financial  transactions  of the Mortgagor.  Mortgagor shall keep such additional
records as may be  necessary  to reflect  its  ownership  and  operation  of the
Mortgaged  Property  and its  activities  thereon.  Mortgagor  shall  permit any
authorized  representatives  of  Mortgagee to inspect such books and records and
the Mortgaged  Property and to make copies and to take extracts therefrom all at
such reasonable times and as often may be reasonably requested.

        2.8 DEFENSE OF TITLE.  Mortgagor shall defend, at its expense,  title to
the  Mortgaged  Property  and the lien and  interest  of  Mortgagee  thereon and
therein and maintain and preserve  such lien and interest and keep this Mortgage
the first  lien upon and prior  perfected  security  interest  in the  Mortgaged
Property.

        2.9 LIENS.  Mortgagor  shall not directly or indirectly  create,  incur,
assume  or permit to exist any lien or  encumbrance  on or with  respect  to the
Mortgaged  Property  or assign or convey  any right to receive  the  production,
proceeds or income therefrom except:  (i) liens for taxes,  assessments or other
governmental  charges  if the  same  shall  not at the  time  be  delinquent  or
thereafter  can be paid without  penalty;  (ii)  statutory  liens of  landlords,
carriers,  warehousemen,  mechanics  and  materialmen  incurred in the  ordinary
course of business and  satisfied or released  prior to  delinquency;  and (iii)
liens incurred or deposits made in the ordinary course of business in connection
with  workers'  compensation  unemployment  insurance  and other types of social
security or to secure (or to obtain  letters of credit or surety or  performance
bonds which secure) the performance of statutory  obligations for reclamation or
which are required in connection with the obtaining of governmental licenses.

        2.10  MAINTENANCE OF OWNERSHIP OF PROPERTY.  Mortgagor shall not convey,
transfer, assign or encumber any interest in the Mortgaged Property or create or
allow to exist any interest

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                                                                   EXHIBIT 10.51

in the  Mortgaged  Property  held by any  person  other  than the  Mortgagor  or
Mortgagee, except as provided in the Acquisition Agreement.

        2.11  NO  CLAIMS  AGAINST  MORTGAGEE,  ETC.  Nothing  contained  in this
Mortgage  shall  constitute  any  consent or request  by  Mortgagee,  express or
implied,  for the  performance of any labor or services or the furnishing of any
materials  or other  property in respect of the  Mortgaged  Property or any part
thereof,  or be construed to permit the making of any claim against Mortgagee in
respect  of  labor or  services  or the  furnishing  of any  materials  or other
property  or any claim that any lien based on the  performance  of such labor or
services or the  furnishing of any such  materials or other property is prior to
the lien of this Mortgage.

        2.12  ASSIGNMENT OF RENTS.  The  assignment of rents,  issues,  incomes,
products,  accessions,  proceeds  and other  benefits  contained  in section 1.1
(collectively,   the  "Benefits")  shall  constitute  an  absolute  and  present
assignment,  subject,  however,  to the conditional  permission  given herein to
Mortgagor to collect and use such  Benefits.  Upon the occurrence and during the
continuance of an Event of Default,  such permission  shall be terminated.  Such
assignment,  including,  without limitation, the termination of such conditional
permission  upon  the  occurrence  and  during  the  continuance  of an Event of
Default,  shall be fully operative without any further action on the part of any
of Mortgagor or Mortgagee. All parties (the "Purchasers") producing, purchasing,
receiving or having in their  possession  any of the Benefits are authorized and
directed to treat and regard  Mortgagee  as the party  entitled  in  Mortgagor's
place  and  stead to  receive  such  Benefit;  and said  parties  shall be fully
protected  in so  treating  and  regarding  Mortgagee  and  shall  be  under  no
obligation to see to the application by Mortgagee of any such Benefits  received
by it.  Mortgagee  shall  apply all of the  Benefits  received  pursuant to this
section  2.12 to  satisfaction  of the  indebtedness  secured by this  Mortgage.
Notwithstanding  the foregoing,  so long as a Purchaser  shall not have received
notice that an Event of Default shall have occurred and be continuing hereunder,
such  Purchaser  shall be fully  protected  and may pay any such  Benefit to the
Mortgagor.  Mortgagee shall be entitled,  at its option, upon the occurrence and
during the  continuance of an Event of Default  hereunder,  to all Benefits from
the  Mortgaged  Property,  whether  or not  Mortgagee  takes  possession  of the
Mortgaged  Property.  Mortgagor  hereby  further  grants to Mortgagee the right,
following  and during the  continuance  of an Event of Default,  at  Mortgagee's
option,  to enter upon and take  possession  of the  Mortgaged  Property for the
purpose of  collecting  the  Benefits.  The  assignment of the Benefits and such
grant shall  continue in effect  until the  indebtedness  and other sums secured
hereby are paid, the execution of this Mortgage  constituting and evidencing the
irrevocable  consent of Mortgagor to the entry upon and taking possession of the
Mortgaged  Property  by  Mortgagee  pursuant  to  such  grant,  whether  or  not
foreclosure has been instituted.

        2.13  ACQUIRED  PROPERTY  SUBJECT  TO  LIEN.  All  property  at any time
acquired by  Mortgagor  and  required by section 1.1 of this  Mortgage to become
subject to the lien  hereof,  whether  such  property is  acquired by  exchange,
purchase,  construction or otherwise, shall forthwith become subject to the lien
of this Mortgage  without  further action on the part of Mortgagor or Mortgagee.
Mortgagor,  at its  expense,  will  execute and deliver to  Mortgagee  (and will
record and file as provided in section 2.2) an instrument  supplemental  to this
Mortgage,

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                                                                   EXHIBIT 10.51

reasonably  satisfactory  in substance and form to  Mortgagee,  whenever such an
instrument  is, in the reasonable  opinion of Mortgagee,  necessary or desirable
under  applicable  law to subject to the lien of this Mortgage all right,  title
and interest of Mortgagor in and to all property required by this Mortgage to be
subjected to the lien hereof and  acquired by  Mortgagor  since the date of this
Mortgage or the date of the most recent  supplemental  instrument  so subjecting
property to the lien hereof,  whichever is later. Mortgagor shall give Mortgagee
written notice of each  acquisition of Mining Claims,  Millsite Claims (patented
or  unpatented)  or  other  real  property   within  15  days  after  each  such
acquisition.

        2.14  NET  WORTH.  Mortgagor  shall  maintain  a  positive  consolidated
tangible net worth determined under generally accepted accounting  principles as
in effect in the United States from time to time.

                                    ARTICLE 3

                 INSURANCE: DAMAGE, DESTRUCTION OR TAKING, ETC.

        3.1 INSURANCE.

        3.1.1 RISKS TO BE INSURED.  Mortgagor will, at its expense,  maintain or
cause to be maintained  with insurers  reasonably  acceptable to Mortgagee,  (a)
all-risk  insurance  in  amounts  not less than 100% of the then full  insurable
value (cost of repairing, replacing,  constructing or reconstructing,  whichever
is the least, with comparable  materials) of the Improvements,  as determined by
Mortgagor in accordance with generally accepted  insurance  practice  reasonably
acceptable  to Mortgagee,  or, upon the request of  Mortgagee,  as determined at
Mortgagor's  expense by the  insurer or  insurers  or by an expert  selected  by
Mortgagee,  (b)  public  liability,  including  bodily and  personal  injury and
property damage,  insurance applicable to the Mortgaged Property in such amounts
as are  usually  carried by prudent  persons  operating  similar  properties  in
Wyoming,  but in any  event  not less than the  amount  of  coverage  maintained
immediately prior to the execution of this Agreement,  (c) worker's compensation
insurance to the full extent  required by  applicable  law for all  employees of
Mortgagor engaged in any work on or about the Mortgaged  Property and employer's
liability  insurance in such amounts as are usually  carried by prudent  persons
operating  similar   properties  in  Wyoming,   and  (d)  such  other  insurance
(including, without limitation, business interruption insurance) with respect to
the  Mortgaged  Property  as is usually  carried by  persons  operating  similar
properties in Wyoming, in such amounts and against such insurable hazards as may
be  available  and as  Mortgagee  from time to time may  reasonably  require  by
written notice to Mortgagor.

        3.1.2 POLICY PROVISIONS.  All insurance maintained by Mortgagor pursuant
to section 3.1.1,  shall (a) (except for worker's  compensation  insurance) name
Mortgagor or its permitted  assignee and Mortgagee as insureds,  mortgagees  and
loss payees as their respective  interests may appear;  (b) (except for worker's
compensation and public liability  insurance)  provide that the proceeds for any
losses shall be adjusted with the insurers by Mortgagor  subject to the approval
of Mortgagee in the event the claimed loss shall exceed $5,000,000, and shall be
payable to

                                        7



<PAGE>


                                                                   EXHIBIT 10.51

Mortgagee and Mortgagor,  or its permitted  assignee,  to be held and applied as
provided in section  3.3;  (c) include  effective  waivers by the insurer of all
rights of subrogation  against any named insured,  the  indebtedness  secured by
this  Mortgage  and  the  Mortgaged   Property  and  all  claims  for  insurance
premiums-against  Mortgagee;  (d)  provide  that any  losses  shall  be  payable
notwithstanding  (i) any act,  failure to act or  negligence  of or violation of
warranties,  declarations  or  conditions  contained in such policy by any named
insured,  (ii) the occupation or use of the Mortgaged Property for purposes more
hazardous than permitted by the terms  thereof,  (iii) any  foreclosure or other
action or  proceeding  taken by  Mortgagee  pursuant  to any  provision  of this
Mortgage, or (i) any change in title or ownership of the Mortgaged Property; (e)
provide that no cancellation, reduction in amount or material change in coverage
thereof shall be effective  until at least 30 days after receipt by Mortgagee of
written  notice  thereof;  and (f) be  satisfactory  in all  other  respects  to
Mortgagee.  Any  insurance  maintained  pursuant  to  this  section  3.1  may be
evidenced by blanket  insurance  policies  covering the  Mortgaged  Property and
other  properties  or assets of  Mortgagor,  provided that any such policy shall
specify the portion, if less than all, of the total coverage of such policy that
is allocated to the Mortgaged  Property and shall in all other  respects  comply
with the requirements of this section 3.1.

        3.1.3  DELIVERY OF POLICIES,  ETC.  Mortgagor will deliver to Mortgagee,
promptly upon request,  (a) duplicate  originals of all policies  evidencing all
insurance  required to be  maintained  under  section  3.1.1 (or, in the case of
blanket  policies,   certificates  thereof  by  the  insurers  together  with  a
counterpart of each blanket  policy),  and (b) evidence as to the payment of all
premiums due thereon (with respect to public liability insurance  policies,  all
installments  for the  current  year due thereon to such  date),  provided  that
Mortgagee  shall not be deemed by reason of their  custody of such  policies  to
have  knowledge  of  the  contents  thereof.  Mortgagor  will  also  deliver  to
Mortgagee, promptly upon request, but not more frequently than once every twelve
months,  Officers'  Certificates  setting forth the  particulars  as to all such
insurance  policies and certifying that the same comply with the requirements of
this section, that all premiums due thereon have been paid and that the same are
in full force and effect.  Mortgagor will also deliver to Mortgagee a new policy
as  replacement  for any  expiring  policy at least 30 days prior to the date of
such  expiration.  In the event  Mortgagor  shall fail to effect or maintain any
insurance  required to be effected or maintained  pursuant to the  provisions of
this section 3.1,  Mortgagor will indemnify  Mortgagee  against damage,  loss or
liability  resulting  from all risks for which  such  insurance  shall have been
effected or maintained.  The obligations of Mortgagor to indemnify  Mortgagee in
such a manner shall  survive any  discharge of this Mortgage and payment in full
of the Note.

        3.1.4 SEPARATE INSURANCE. Mortgagor will not take out separate insurance
concurrent in form or contributing in the event of loss with that required to be
maintained pursuant to this section.

        3.2 DAMAGE,  DESTRUCTION OR TAKING; MORTGAGOR TO GIVE NOTICE; ASSIGNMENT
OF AWARDS. In case of (a) any damage to or destruction of the Mortgaged Property
or any part thereof,  or (b) any taking (whether for permanent or temporary use)
of all or any part of the  Mortgaged  Property or any interest  therein or right
accruing thereto, as the result of or in lieu or in anticipation of the exercise
of the right of condemnation  or eminent domain,  or a change of grade affecting
the

                                        8



<PAGE>


                                                                   EXHIBIT 10.51

Mortgaged Property or any part thereof (a "Taking"),  or the commencement of any
proceedings  or  negotiations  which might result in any such Taking,  Mortgagor
will promptly give written notice thereof to Mortgagee, generally describing the
nature and extent of such damage or  destruction or of such Taking or the nature
of such  proceedings  or  negotiations  and the  nature and extent of the Taking
which might result therefrom, as the case may be. Mortgagee shall be entitled to
all insurance  proceeds  payable on account of such damage or destruction and to
all awards or payments  allocable to the  Mortgaged  Property on account of such
Taking and  Mortgagor  hereby  irrevocably  assigns,  transfers and sets over to
Mortgagee  all rights of  Mortgagor to any such  proceeds,  award or payment and
irrevocably  authorize and empower  Mortgagee,  at their option,  in the name of
Mortgagor  or  otherwise,   to  file  and  prosecute  what  would  otherwise  be
Mortgagor's  claim for any such  proceeds,  award or payment  and,  to  collect,
receipt for and retain the same for  disposition in accordance  with section 3.3
Mortgagor  will pay all reasonable  costs and expenses  incurred by Mortgagee in
connection with any such damage, destruction or Taking and seeking and obtaining
any insurance proceeds, award or payment in respect thereof.

        3.3 APPLICATION OF PROCEEDS. Mortgagee shall apply all amounts recovered
under any insurance policy required to be maintained by Mortgagor hereunder, and
all net awards  received by it on account of any Taking in the  following  ways:
(a) so long as no  Event of  Default  shall  have  occurred  and be  continuing,
released to Mortgagor for  application  to the cost of  compliance  with section
3.5,  or (b) if an Event of  Default  has  occurred  and is  continuing,  (i) to
fulfill any of the covenants  contained  herein as Mortgagee may  determine,  or
(ii) to be held as  additional  cash  collateral  hereunder  to be  invested  in
short-term  United States government  securities  selected by Mortgagor with the
consent of Mortgagee.

        3.4 TOTAL TAKING AND TOTAL  DESTRUCTION.  In case of (a) a Taking of the
entire  Mortgaged  Property,  or (b) a Taking of less than the entire  Mortgaged
Property, or any material damage to or destruction of the Mortgaged Property, in
either  case  which,  in the good  faith  judgment  of  Mortgagee,  renders  the
Mortgaged Property remaining after such Taking, damage or destruction,  taken as
a whole,  unsuitable for  restoration for use as property of  substantially  the
same value,  condition,  character and general utility as the Mortgaged Property
prior to such Taking, damage or destruction (any such Taking being herein called
a "Total Taking" and any such damage or destruction being herein called a "Total
Destruction"),  then the  proceeds of insurance  and the net awards  received by
Mortgagee  or  Mortgagor  on account of such Total  Taking or Total  Destruction
shall be applied by Mortgagee as follows:

               FIRST:  to the payment of the costs and  expenses of the recovery
        of such proceeds or awards (including,  without  limitation,  attorneys'
        fees) and any taxes,  assessments or charges,  prior to the lien of this
        Mortgage, which Mortgagee may consider it necessary or desirable to pay;

               SECOND:  to the  payment  of any  indebtedness  secured  by  this
        Mortgage,  other than  indebtedness with respect to the Note at the time
        outstanding,  which  Mortgagee may consider it necessary or desirable to
        pay;

                                        9



<PAGE>


                                                                   EXHIBIT 10.51

               THIRD:  to the payment of all amounts of principal,  and interest
        at the time  outstanding on the Note (whether or not at the time due and
        payable by reason of maturity or as an installment of combined principal
        and  interest  or  by  reason  of  any  prepayment   requirement  or  by
        declaration of  acceleration  or otherwise),  including  interest at the
        rate per annum set forth in the Note for past due amounts (the  "Default
        Rate") on any  overdue  principal  and (to the  extent  permitted  under
        applicable law) on any overdue  interest;  and in case such moneys shall
        be  insufficient  to pay in full the  amounts so due and unpaid upon the
        Note at the time outstanding, then, FIRST, to the payment of all amounts
        of  interest at the time  outstanding  on the Note,  and SECOND,  to the
        payment of all  amounts of  principal,  at the time  outstanding  on the
        Note.

               FOURTH:  the balance,  if any, held by Mortgagee after payment in
        full of all amounts referred to in subdivisions  First, Second and Third
        above,  shall,  unless a court of competent  jurisdiction  may otherwise
        direct by final  order not  subject  to  appeal,  be paid to or upon the
        direction of Mortgagor or its permitted assignee.

        3.5  RESTORATION.  In case of any Taking  (other than a Total Taking) or
any damage to or  destruction  of the  Mortgaged  Property  or any part  thereof
(other than a Total  Destruction),  Mortgagor  will (to the extent such  Taking,
damage or  destruction is susceptible  of  replacement,  repair or  restoration)
commence  or cause to be  commenced,  promptly  and with due  diligence,  at its
expense, whether or not the insurance proceeds for such damage or destruction or
the  award  for such  Taking  shall be  sufficient  for  such  purpose,  (a) the
replacement,  repair  or  restoration  of the  Mortgaged  Property  as nearly as
practicable  (in the case of a Taking,  after giving  effect to any reduction in
area caused  thereby) to the value,  condition,  character  and general  utility
thereof  immediately  prior to such  damage,  destruction  or  Taking or (b) the
substitution  for such Mortgaged  Property or any part thereof of other property
(which shall upon such substitution  become a part of the Mortgaged Property) of
at least the same value and general  utility of such Mortgaged  Property or part
thereof immediately prior to such damage, destruction or Taking.

                                    ARTICLE 4

                          ENVIRONMENTAL INDEMNIFICATION

        4.1  INDEMNIFICATION.   Mortgagor  shall  defend,   indemnify  and  hold
Mortgagee harmless from and against any and all environmental claims directly or
indirectly  arising  out of or  resulting  from any  Hazardous  Substance  being
present or released  in, on,  around or  potentially  affecting  any part of the
Mortgaged  Property or the soil,  vadose zone,  groundwater  or soil vapor on or
under the Mortgaged Property, including:

        4.1.1 Any claim for such  environmental  claim  asserted by any federal,
state, or local governmental  agency,  including the United States Environmental
Protection  Agency and the  Wyoming  Department  of  Environmental  Quality  and
including any claim that  Mortgagee is liable for any such  environmental  claim
asserted as an "owner" or  "operator" of the  Mortgaged  Property  under any law
relating to Hazardous Substances; and

                                       10



<PAGE>


                                                                   EXHIBIT 10.51

        4.1.2 Any such  environmental  claim asserted  against  Mortgagee by any
person other than a governmental  agency,  including any person who may purchase
or lease all or any  portion of the  Mortgaged  Property  from  Mortgagor,  from
Mortgagee, or from any other purchaser or lessee; any person who may at any time
have any interest in all or any portion of the  Mortgaged  Property;  any person
who may at any time be responsible for any cleanup costs or other  environmental
claims relating to the Mortgaged Property;  and any person claiming to have been
injured in any way as a result of exposure to any  Hazardous  Substance  from or
located at the Mortgaged Property; and

        4.1.3 Any such environmental  claims which Mortgagee reasonably believes
at any time may be incurred to comply with any law, judgment,  order, regulation
or regulatory  directive  relating to Hazardous  Substances  or which  Mortgagee
reasonably  believes at any time may be incurred to protect the public health or
safety; and

        4.1.4 Any such  environmental  claims resulting from currently  existing
conditions  in, on, around or  potentially  affecting  the  Mortgaged  Property,
whether  known or unknown by Mortgagor or Mortgagee at the time this Mortgage is
executed,  and any such  indemnified  costs  resulting  from the  activities  of
Mortgagor,   Mortgagor's  tenants,  or  any  other  person  in,  on,  around  or
potentially affecting the Mortgaged Property.

        4.2 INSPECTION.  Mortgagee, its contractors,  agents and representatives
(hereinafter,  "Site Reviewers") shall have the right at any reasonable time and
from time to time,  upon prior  notice,  to enter  upon and visit the  Mortgaged
Property  for the  purposes of  observing  the  environmental  condition  at the
Mortgaged  Property,  taking  and  removing  soil or  groundwater  samples,  and
conducting tests and/or site  assessments on any part of the Mortgaged  Property
(collectively,  "Site Assessments") for the purpose of determining whether there
exists on the Mortgaged  Property any environmental  condition that could result
in any liability,  cost, or expense to the owner,  occupier, or operator of such
Mortgaged Property arising under any Environmental Laws. The Site Reviewers have
no duty, however,  to conduct any Site Assessment,  and no Site Assessment shall
impose any liability on any Site  Reviewer.  In no event shall the completion of
any Site Assessment be a representation that Hazardous Substances are or are not
present in, on, under or around the Mortgaged  Property,  or that there has been
or shall be  compliance  with any law,  regulation  or ordinance  pertaining  to
Hazardous  Substances or any other  governmental  law. Neither Mortgagor nor any
other party is entitled to rely on any Site Assessment conducted by or on behalf
of  Mortgagee,  which Site  Assessment  shall be for the sole benefit and use of
Mortgagee.  The Site  Reviewers owe no duty of care to protect  Mortgagor or any
other party against, or to inform Mortgagor or any other party of, any Hazardous
Substances or any other  adverse  condition  affecting  the Mortgaged  Property.
Mortgagee shall avoid interfering with Mortgagor's use of the Mortgaged Property
in exercising any rights provided in this Section. The Site Reviewers are hereby
authorized  to enter upon the  Mortgaged  Property for the purpose of conducting
Site  Assessments.  The Site  Reviewers  are further  authorized to perform both
above and below the ground testing for  environmental  damage or the presence of
Hazardous  Substances  on the  Mortgaged  Property  and such other  tests on the
Mortgaged  Property as may be necessary to conduct the site  Assessments  in the
reasonable

                                       11



<PAGE>


                                                                   EXHIBIT 10.51

opinion of the Site  Reviewers,  provided that in conducting  such testing,  the
Site  Reviewers  comply with the  requirements  of the  Federal  Mine Safety and
Health Act and all applicable health and safety laws of the State of Wyoming and
local  authorities  having   jurisdiction  and  Mortgagor's   reasonable  safety
regulations while on the Mortgaged  Property.  Mortgagor will supply to the Site
Reviewers such  historical and operational  information  regarding the Mortgaged
Property as may be reasonably  requested by the Site Reviewers to facilitate the
Site  Assessments  and will make  available for meetings with the Site Reviewers
appropriate  personnel having knowledge of such matters.  The cost of performing
such Site Assessments shall be paid by Mortgagor upon demand of Mortgagee if the
need for the Site  Assessment  arises from or relates to or confirms any release
of Hazardous  Substances  or  noncompliance  with or violation of  Environmental
Laws.  On request,  Mortgagee  shall make the  results of such Site  Assessments
fully  available to  Mortgagor  provided  that  Mortgagor  has fully  reimbursed
Mortgagee for the cost of such Site Assessments.

        4.3 ACTIONS BY MORTGAGEE.  Mortgagee  shall have the right,  but not the
obligation,  without in any way limiting  Mortgagee's  other rights and remedies
under the Note and this  Agreement,  to enter onto the Mortgaged  Property or to
take such other actions as it deems  necessary or advisable to clean up, remove,
resolve,  or  minimize  the impact of, or  otherwise  deal with,  any release of
Hazardous  Substances on or affecting the Mortgaged  Property or any presence of
Hazardous  Substances  on or affecting  the  Mortgaged  Property  that is not in
compliance  with or is in violation of applicable  Environmental  Laws following
receipt of any notice from any person or entity  asserting  the existence of any
Hazardous  Substances  pertaining to the Mortgaged  Property or any part thereof
that, if true, could result in an claim, order,  notice,  suit,  imposition of a
lien on the Mortgaged Property, or other action and/or that, in Mortgagee's sole
opinion,   could  jeopardize  Mortgagee's  security  under  the  Note  and  this
Agreement, if the Mortgagor,  following written notice from Mortgagee shall fail
to promptly take  reasonable  action to prevent any ongoing or future release or
to remedy the effects of any such release, or to cause the presence of Hazardous
Substances  on or affecting  the  Mortgaged  Property to be in  compliance  with
applicable Environmental Laws, diligently prosecute the same to completion,  and
provide  satisfactory  proof of such  preventative  or  remedial  measures.  All
reasonable  costs and expenses  paid or incurred by Mortgagee in the exercise of
any such  rights  shall be  secured  by this  Agreement  and shall be payable by
Mortgagor upon demand.

        4.4  INTERVENTION.  Mortgagee shall have the right at any time to appear
in and to participate in, as a party if it elects, and be represented by counsel
of its  own  choice  in,  any  action  or  proceeding  in  connection  with  any
Environmental Law that affects the Mortgaged Property. Upon demand by Mortgagee,
Mortgagor  shall defend any  investigation,  action or proceeding  involving any
matter  covered  by  Mortgagor's  obligations  hereunder  which  is  brought  or
commenced  against  Mortgagee,  whether alone or together with  Mortgagor or any
other person, all at Mortgagor's own cost and by counsel  reasonably  acceptable
to Mortgagee in the exercise of its  reasonable  judgment.  In the  alternative,
Mortgagee may elect to conduct its own defense at the expense of Mortgagor.

                                       12



<PAGE>


                                                                   EXHIBIT 10.51

        4.5 NONEXCLUSIVITY.  Nothing in this Article shall be construed to limit
any  claim or right  which  Mortgagee  may  otherwise  have at any time  against
Mortgagor or any other person  arising from any source other than this  Article,
including any claim for fraud,  misrepresentation,  waste, or breach of contract
other  than the Note  and this  Mortgage,  and any  rights  of  contribution  or
indemnity under federal,  state or local  environmental  law or other applicable
law, regulation or ordinance.

                                    ARTICLE 5

                        EVENTS OF DEFAULT; REMEDIES, ETC.

        5.1 EVENTS OF DEFAULT; DECLARATION OF NOTE DUE.

          (a)  Events of  Default"  under the Note  shall  constitute  events of
default  hereunder and are herein called "Events of Default".  Events of Default
shall also include:

              (i) The breach or default by Mortgagor  of or under any  covenant,
          warranty, agreement, representation, performance or requirement herein
          contained  or  contained  in the Note which  continues at least thirty
          (30) days after notice to  Mortgagor,  provided that if such breach or
          default  requires  more than  thirty  (30) days to cure and  Mortgagee
          initiates  such cure within such thirty (30) day period and diligently
          pursues the same,  Mortgagor shall have such additional time as may be
          necessary to effect  cure,  but in no event may such  additional  time
          exceed ninety (90) days.

              (ii) The institution of any proceeding against the Mortgagor,  the
          Mortgaged  Property,  or  any  other  property  interest  which  is  a
          co-tenancy  or a joint  interest  in any  property  which is wholly or
          partially  subject to the lien created  hereunder in which forfeiture,
          attachment,  or replevin of any material  asset of Mortgagor is sought
          in the proceeding,  unless such  proceeding is dismissed  within sixty
          (60) days following its initiation.

              (iii) The  admission in writing by Mortgagor  that it is unable to
          pay its debts as they  mature or that it is  generally  not paying its
          debts as they mature.

              (iv) The  liquidation,  termination,  or  dissolution of Mortgagor
          under the laws of the state under which it is organized.

              (v) The  sale,  merger,  lease,  exchange,  conveyance,  transfer,
          mortgage, assignment, pledge or encumbrance of the Mortgaged Property,
          either  voluntarily  or  involuntarily,  or  the  agreement  to do so,
          contrary to the  provisions of the Mortgage  without the prior written
          consent of the Mortgagee being first obtained.

              (vi) The filing of any petition or the commencement of any case or
          proceeding  by or  against  Mortgagor  under any  federal or state law
          relating to insolvency,  bankruptcy,  or  reorganization,  unless such
          petition  and the case or  proceeding  initiated  thereby is dismissed
          within  sixty  (60)  days  from  the  date  of  such  filing;   or  an
          adjudication that Mortgagor is insolvent

                                       13



<PAGE>


                                                                   EXHIBIT 10.51

or  bankrupt;  or the  entry of an order for  relief  under  the  United  States
Bankruptcy Code with respect to Mortgagor;  the filing of an answer by Mortgagor
admitting the  allegations  of any such petition;  or the  appointment of or the
taking of possession by a custodian, trustee or receiver for all or any material
assets of  Mortgagor,  unless such  appointment  is vacated or dismissed or such
possession  is  terminated  within  sixty  (60)  days  from  the  date  of  such
appointment or commencement of such possession, but not later than five (5) days
before the proposed sale of any material  assets of Mortgagor by such custodian,
trustee,  or  receiver,  other than in the  ordinary  course of the  business of
Mortgagor.

              (vii) The insolvency of Borrower;  or the execution by Borrower of
          an  assignment  for the  benefit of  creditors;  or the  convening  by
          Borrower of a meeting of its creditors,  or any class thereof, for the
          purposes of effecting a moratorium upon or extension or composition of
          its debts;  or the failure of Borrower to  generally  pay its debts as
          they mature.

              (viii) The failure to place into production an economically viable
          uranium mine on the Mortgaged Property by December 31, 2005.

              (b) Upon the occurrence  and during the  continuance of any of the
          Events of  Default,  and  whether or not any amount due under the Note
          has been  declared due and payable  pursuant to the Note,  then and in
          any such event Mortgagee may declare,  by written notice to Mortgagor,
          all indebtedness secured hereby,  including,  indebtedness accelerated
          pursuant to the Note, to be due and payable upon the date specified in
          such notice, and upon such date the same shall become due and payable,
          together with interest accrued thereon,  without presentment,  demand,
          protest,  notice or other  requirements  of any kind, all of which are
          hereby waived.

          (c)  Mortgagor  will pay on demand all costs and expenses  (including,
without  limitation,  attorneys' fees and expenses)  incurred by or on behalf of
Mortgagee in enforcing this Mortgage or the Note or occasioned by any default or
Event of Default under this Mortgage.

          (d) Upon the  occurrence  and  during the  continuance  of an Event of
Default,  interest at the Default Rate shall be due and payable on the principal
of, premium,  if any, and (to the extent  permitted by law) interest on the Note
at the time outstanding and all other indebtedness secured hereby.

        5.2 LEGAL PROCEEDINGS;  FORECLOSURE;  RESCISSION. If an Event of Default
shall  have  occurred  and be  continuing,  Mortgagee  at any time  may,  at its
election, proceed at law or in equity or otherwise to enforce the payment of the
Note at the time outstanding in accordance with the terms hereof and thereof and
to  foreclose  the  lien of this  Mortgage  as  against  all or any  part of the
Mortgaged  Property or proceed to take either of such  actions,  and to have the
same sold under the  judgment  or decree of a court of  competent  jurisdiction.
Mortgagee,  from time to time before sale,  may rescind any notice of breach and
election to sell by executing,  delivering  and causing to be recorded a written
notice of such rescission. The exercise by Mortgagee of such right of rescission
shall  not  constitute  a waiver of any  breach  or  default  then  existing  or
subsequently  occurring,  or impair  the  rights of  Mortgagee  to  execute  and
deliver, as above

                                       14



<PAGE>


                                                                   EXHIBIT 10.51

provided, other notices of breach and election to sell, nor otherwise affect any
term,  covenant or condition hereof or under any obligations  secured hereby, or
any of the rights, obligations or remedies of the parties thereunder.

        5.3 POWER OF SALE.  If an Event of Default  shall have  occurred  and be
continuing,  Mortgagee may sell, assign, transfer and deliver the whole or, from
time to time,  any part of the Mortgaged  Property,  or any interest in any part
thereof,  for cash,  on credit or for other  property,  for  immediate or future
delivery,  and for such price or prices and on such  terms as  Mortgagee  in its
reasonable  discretion  may  determine,  or as  may  be  required  by  law.  The
provisions of this Mortgage shall be interpreted as broadly as possible to allow
Mortgagee the full advantage of all remedies to which Mortgagors under mortgages
are  entitled  under  Wyoming law.  Without in any way  limiting the  foregoing,
Mortgagor  agrees  that  Mortgagee  shall have the right  following  an Event of
Default hereunder to proceed with either a judicial foreclosure,  or foreclosure
by advertisement pursuant to Section 34-4-101,  et.seq., of the Wyoming Statutes
Annotated, as amended. In addition, with respect to any portion of the Mortgaged
Property that  constitutes  personal  property  governed by the Wyoming  Uniform
Commercial  Code, this Mortgage shall be construed  broadly to give to Mortgagee
all of the rights and remedies to which  secured  parties are or may be entitled
under the Wyoming Uniform Commercial Code.

        5.4 MORTGAGEE  AUTHORIZED TO EXECUTE DEEDS, ETC.  Mortgagor  irrevocably
appoints Mortgagee,  collectively, the true and lawful attorney of Mortgagor, in
its name and stead and on its behalf,  for the purpose of effectuating any sale,
assignment, transfer or delivery for the enforcement hereof, whether pursuant to
power of sale, foreclosure by advertisement,  judicial foreclosure or otherwise,
to execute  and deliver all such  deeds,  bills of sale,  assignments  and other
instruments as Mortgagee may consider necessary or appropriate,  with full power
of  substitution,  Mortgagor  hereby  ratifying and confirming all that its said
attorney or any substitute shall lawfully do by virtue hereof. Nevertheless,  if
so requested by Mortgagee or any  purchaser,  Mortgagor  will ratify and confirm
any such sale,  assignment,  transfer or delivery by executing and delivering to
Mortgagee or such purchaser all such proper deeds,  bills of sale,  assignments,
releases and other instruments as may be designated in any such request.  If, in
the judgment of the Mortgagee,  time permits,  Mortgagee shall give prior notice
to the Mortgagor of the exercise of its powers hereunder, and give the Mortgagor
the opportunity to perform any act authorized  hereby.  The failure of Mortgagee
to comply with the preceding  sentence shall not affect its powers  hereunder or
in any way limit or prejudice its rights or remedies hereunder.

        5.5 PURCHASE OF MORTGAGED  PROPERTY BY  MORTGAGEE.  The Mortgagee or any
successor holder of the Note may be a purchaser of the Mortgaged  Property or of
any  part  thereof  or of any  interest  therein  at any sale  thereof,  whether
pursuant to power of sale, foreclosure by advertisement, judicial foreclosure or
otherwise,  and shall apply upon the  purchase  price  thereof the  indebtedness
secured  hereby  owing to such  purchaser,  to the  extent  of such  purchaser's
distributive  share of the purchase price.  Any such purchaser  shall,  upon any
such purchase,  acquire good title to the  properties so purchased,  free of the
lien of this Mortgage and free of all rights of redemption in Mortgagor.

                                       15



<PAGE>


                                                                   EXHIBIT 10.51

        5.6 RECEIPT A SUFFICIENT  DISCHARGE TO  PURCHASER.  Upon any sale of the
Mortgaged Property or any part thereof or any interest therein, whether pursuant
to  power  of  sale,  foreclosure  by  advertisement,  judicial  foreclosure  or
otherwise,  the receipt of the purchase money by Mortgagee or the officer making
the sale under  judicial  proceedings  shall be a  sufficient  discharge  to the
purchaser for the purchase money, and such purchaser shall not be obliged to see
to the application thereof.

        5.7 WAIVER OF APPRAISEMENT,  VALUATION, ETC. Mortgagor hereby waives, to
the  fullest  extent it may  lawfully  do so, the  benefit of all  appraisement,
valuation, stay, extension and redemption laws now or hereafter in force and all
rights of marshaling  in the event of any sale of the Mortgaged  Property or any
part thereof or any interest therein.

        5.8 SALE A BAR AGAINST MORTGAGOR.  Any sale of the Mortgaged Property or
any part thereof or any interest  therein  under or by virtue of this  Mortgage,
whether pursuant to foreclosure by advertisement,  judicial foreclosure or power
of sale or  otherwise,  shall  forever be a  perpetual  bar  against  Mortgagor,
provided  that  nothing  contained in this section 5.8 shall limit any rights of
Mortgagor  against  the  Mortgagee  resulting  from  any  unlawful  sale  of the
Mortgaged Property or any part thereof or interest therein.

        5.9 NOTE TO BECOME DUE ON SALE.  Upon any sale by Mortgagee  under or by
virtue of this Mortgage,  whether pursuant to judicial foreclosure,  foreclosure
by  advertisement  or power of sale or otherwise,  the entire  unpaid  principal
amount of the Note at the time outstanding shall, if not previously declared due
and payable,  immediately become due and payable, together with interest accrued
thereon, and all other indebtedness which this Mortgage by its terms secures.

        5.10  APPLICATION OF PROCEEDS OF SALE AND OTHER MONEYS.  The proceeds of
any sale of the Mortgaged  Property or any part thereof or any interest  therein
under or by virtue of this Mortgage,  whether pursuant to judicial  foreclosure,
foreclosure by advertisement,  power of sale, or otherwise, shall, to the extent
allowed by law, be applied as follows:

              FIRST:  to the  payment  of all  costs and  expenses  of such sale
          (including,  without  limitation,  the cost of evidence of title,  the
          costs and expenses, if any, of taking possession of, retaining custody
          over, repairing,  maintaining and preserving the Mortgaged Property or
          any part  thereof  prior to such sale),  all costs and expenses of any
          receiver of the Mortgaged Property or any part thereof, and any taxes,
          assessments,  encumbrances, liens or charges, prior to the lien of, or
          security  interest  created by, this  Mortgage,  which  Mortgagee  may
          consider it necessary or desirable to pay;

              SECOND:  to  the  payment  of any  indebtedness  secured  by  this
          Mortgage, other than indebtedness with respect to the Note at the time
          outstanding, which Mortgagee may consider it necessary or desirable to
          pay;

              THIRD: to the payment of all amounts of principal, and interest at
          the  time due and  payable  on the Note  outstanding  (whether  due by
          reason of maturity or as an installment

                                       16



<PAGE>


                                                                   EXHIBIT 10.51

        of  combined  principal  and  interest  or by reason  of any  prepayment
        requirement or by declaration or acceleration  or otherwise),  including
        interest at the Default Rate on any overdue  principal  and premium,  if
        any, and (to the extent  permitted under  applicable law) on any overdue
        interest;  and in case such moneys shall be  insufficient to pay in full
        the  amounts  so due and unpaid  upon the Note at the time  outstanding,
        then,  first,  to the payment of all amounts of interest at the time due
        and payable on the Note,  and  second,  to the payment of all amounts of
        principal and premium,  if any, at the time due and payable on the Note;
        and

              FOURTH:  the balance,  if any, held by Mortgagee  after payment in
          full of all amounts  referred  to in  subdivisions  First,  Second and
          Third  above,  shall,  unless a court of  competent  jurisdiction  may
          otherwise direct, be paid to or upon the direction of Mortgagor or its
          permitted assignee.

        5.11 APPOINTMENT OF RECEIVER. If an Event of Default shall have occurred
and be continuing,  Mortgagee  shall,  as a matter of right,  be entitled to the
appointment of a receiver for all or any part of the Mortgaged Property, whether
such receivership be incidental to a proposed sale of the Mortgaged  Property or
otherwise.

        5.12  POSSESSION,  MANAGEMENT  AND INCOME.  If an Event of Default shall
have occurred and be continuing, Mortgagee may, but shall be under no obligation
to,  immediately enter upon and take possession of the Mortgaged Property or any
part thereof by force, summary proceeding, ejectment or otherwise and may remove
Mortgagor and all other persons and any and all property therefrom and may hold,
operate,  maintain,  repair,  preserve  and  manage  the  same and  receive  all
earnings,  income,  rents,  issues and proceeds accruing with respect thereto or
any part thereof.  Mortgagee  shall be under no liability to Mortgagor for or by
reason of any such taking of possession, entry, removal or holding, operation or
management, except that any amounts so received by Mortgagee shall be applied to
pay all costs and expenses of so entering upon,  taking  possession of, holding,
operating,  maintaining,   repairing,  preserving  and  managing  the  Mortgaged
Property or any part thereof, and any taxes,  assessments or other charges prior
to the lien of this  Mortgage  which  Mortgagee  may  consider it  necessary  or
desirable to pay,  and any balance of such amounts  shall be applied as provided
in section 5.10.

        5.13  RIGHT OF  MORTGAGEE  TO PERFORM  MORTGAGOR'S  COVENANTS,  ETC.  If
Mortgagor  shall fail to make any payment or perform any act required to be made
or performed  hereunder,  Mortgagee  without notice to or demand upon Mortgagor,
and without  waiving or releasing any  obligation  or default,  may but shall be
under no obligation to) at any time thereafter make such payment or perform such
act for the  account  and at the  expense of  Mortgagor,  and may enter upon the
Mortgaged  Property  for such  purpose and take all such  action  thereon as, in
Mortgagee's opinion, may be necessary or appropriate therefor. No such entry and
no such  action  shall-be  deemed an  eviction  of any  lessee of the  Mortgaged
Property or any part  thereof.  All sums so paid by Mortgagee  and all costs and
expenses  (including,  without  limitation,  attorneys'  fees and  expenses)  so
incurred,  together with  interest  thereon at the Default Rate from the date of
payment or incurring,  shall constitute additional  indebtedness secured by this
Mortgage and shall be paid by

                                       17



<PAGE>


                                                                   EXHIBIT 10.51

Mortgagor to Mortgagee on demand.  The final two  sentences of Section 5.4 shall
apply to the exercise to the rights granted by this Section 5.13.

        5.14  REMEDIES,  ETC.,  CUMULATIVE.  Each  right,  power  and  remedy of
Mortgagee  provided for in this Mortgage or now or hereafter  existing at law or
in equity or by statute or otherwise  shall be  cumulative  and  concurrent  and
shall be in addition to every other right,  power or remedy provided for in this
Mortgage  or now or  hereafter  existing  at law or in equity or by  statute  or
otherwise, and the exercise or beginning of the exercise by Mortgagee of any one
or more of the rights,  powers or remedies  provided for in this Mortgage or now
or hereafter  existing at law or in equity or by statute or otherwise  shall not
preclude  the  simultaneous  or later  exercise by  Mortgagee of any or all such
other rights, powers or remedies.

        5.15 ATTORNEYS' FEES ETC.  Mortgagor shall pay to Mortgagee,  on demand,
any costs and expenses,  including reasonable attorneys' fees and expenses, paid
or incurred by Mortgagee in connection with the collection of any amount payable
by Mortgagor to Mortgagee  hereunder or under the Note, whether or not any legal
proceeding is commenced  hereunder or thereunder and whether or not any Event of
Default shall have occurred and is continuing, together with interest thereon at
the Default Rate from the date of payment or  incurring by Mortgagee  until paid
by Mortgagor.

        5.16  PROVISIONS  SUBJECT TO  APPLICABLE  LAW.  All  rights,  powers and
remedies  provided in this Mortgage may be exercised only to the extent that the
exercise  thereof  does not violate  any  applicable  provisions  of law and are
intended to be limited to the extent necessary so that they will not render this
Mortgage  invalid,  unenforceable or not entitled to be recorded,  registered or
filed under the provisions of any  applicable  law. If any term of this Mortgage
or any application  thereof shall be invalid or unenforceable,  the remainder of
this  Mortgage  and any other  application  of such term  shall not be  affected
thereby.

        5.17 NO WAIVER,  ETC. No failure by  Mortgagee to insist upon the strict
performance  of any term hereof or thereof,  or to exercise any right,  power or
remedy consequent upon a breach hereof or thereof,  shall constitute a waiver of
any such term or of any such  breach.  No waiver of any breach  shall  affect or
alter this Mortgage,  which shall continue in full force and effect with respect
to any other then existing or  subsequent  breach.  By accepting  payment of any
amount secured hereby after its due date, Mortgagee shall not be deemed to waive
its right either to require prompt payment when due of all other amounts payable
hereunder or to declare a default for failure to effect such prompt payment.

        5.18 COMPROMISE OF ACTIONS,  ETC. Any action, suit or proceeding brought
by Mortgagee pursuant to any of the terms of this Mortgage or otherwise, and any
claim made by Mortgagee  hereunder  may be  compromised,  withdrawn or otherwise
dealt with by Mortgagee without any notice to or approval of Mortgagor.

                                       18



<PAGE>


                                                                   EXHIBIT 10.51

                                    ARTICLE 6

                                  MISCELLANEOUS

        6.1  FURTHER  ASSURANCES.  Mortgagor,  at  its  expense,  will  execute,
acknowledge  and  deliver  all such  instruments  and take  all such  action  as
Mortgagee  from time to time may reasonably  request for the better  assuring to
Mortgagee  the  properties  and rights now or  hereafter  subjected  to the lien
hereof or assigned  hereunder  or intended so to be.  Notwithstanding  any other
provision of this Mortgage,  Mortgagor hereby agrees that,  without notice to or
the  consent  of  Mortgagor,  Mortgagee  may file  with the  appropriate  public
officials  such financing  statements or similar  documents as are or may become
necessary  to perfect and  continue  the  perfection  of the  security  interest
granted by this Mortgage.

        6.2 ADDITIONAL SECURITY.  Without notice to or consent of Mortgagor, and
without  impairment of the lien and rights created by this  Mortgage,  Mortgagee
may accept (but  Mortgagor  shall not be obligated to furnish) from Mortgagor or
from any other person additional  security for the Note at the time outstanding.
Neither the giving of this Mortgage nor the  acceptance  of any such  additional
security  shall prevent  Mortgagee from  resorting,  first,  to such  additional
security,  or, first, to the security created by this Mortgage,  or concurrently
to both, in any case without  affecting  Mortgagee's  lien and rights under this
Mortgage.

        6.3  RELEASE,  PARTIAL  RELEASE,  ETC.  Upon receipt of all sums secured
hereby,  Mortgagee  shall  release  without  warranty  the  property  then  held
hereunder.  Mortgagee may, at any time and from time to time,  without liability
therefor,  release any part of the Mortgaged Property,  consent to the making of
any map or plat  thereof,  grant an  easement  thereon,  grant an  extension  or
subordinate  the lien of this  Mortgage,  or enter into any other  agreement  in
connection with the Mortgaged Property.

        6.4 NOTICES, ETC. All notices, demands,  requests,  consents,  approvals
and other instruments under this Mortgage shall be in writing  (including telex,
telecopy and  telegraphic  communication)  and mailed,  telexed,  telegraphed or
delivered,  at the following  addresses or, as to any party,  at such address as
shall be designated by such party in a written notice to the other parties.

If to Mortgagor:                          If to Mortgagee:

      Kennecott Uranium Company                Kennecott Energy Company
      Attn:  Gregory H. Boyce                  Attn:  Lynn R. Cardey-Yates
      Kennecott Energy Company                 8315 West 3595 South
      Caller Box 3009                          P.O. Box 6001
      505 South Gillette Avenue                Magna, UT  84044-6001
      Gillette, WY  82717-3009                 Fax: (801) 252-3559
      Fax: (307) 687-6011

                                       19



<PAGE>


                                                                   EXHIBIT 10.51

With Mortgagee Copy to:

     Parsons Behle & Latimer
     Lawrence R. Barusch
     201 South Main Street, Suite 1800
     Salt Lake City, Utah  84111
     Fax: (801) 536-6111

All such  notices  and  communications  shall,  when  mailed  by  registered  or
certified mail, or otherwise physically delivered, be effective when received or
delivered, addressed as aforesaid, and, when sent by ordinary mail, be effective
five days after the day on which deposited in the mails, addressed as aforesaid,
and when telexed or telecopied, be effective upon confirmation of transmission.

        6.5 AMENDMENTS AND WAIVERS. This Mortgage, the Note, and any term hereof
or thereof may be amended,  discharged or terminated  and the  observance of any
term of this  Mortgage  or the  Note may be  waived  (either  generally  or in a
particular  instance  and  either  retroactively  or  prospectively)  only by an
instrument in writing signed by Mortgagor and Mortgagee.

        6.6  EXPENSES.  Mortgagor  will  pay or cause to be paid (a) the cost of
filing and  recording of this  Mortgage and Uniform  Commercial  Code  financing
statements  and any other  documents to be filed or recorded in connection  with
the  execution  and  delivery  hereof or thereof;  and (b) all taxes  (including
interest and penalties) at any time payable in connection with the execution and
delivery of this Mortgage and any other instruments or agreements related hereto
or thereto,  any amendment or waiver relating  hereto or thereto,  the issue and
acquisition  of the Note  and,  where  applicable,  such  filing  and  recording
(Mortgagor  agreeing to indemnify  Mortgagee in respect of such taxes,  interest
and penalties.)

        6.7 [Intentionally Omitted.]

        6.8   WAIVER  OF  JURY   TRIAL.   MORTGAGOR   HEREBY   IRREVOCABLY   AND
UNCONDITIONALLY  WAIVES  THE  RIGHT TO TRIAL BY JURY IN ANY  LEGAL OR  EQUITABLE
ACTION, SUIT OR PROCEEDING ARISING OUT OF OR RELATING TO THIS MORTGAGE, THE NOTE
OR ANY TRANSACTION CONTEMPLATED HEREBY OR THEREBY.

        6.9 MISCELLANEOUS.  All the terms of this Mortgage shall apply to and be
binding upon (and those  provisions of this Mortgage  explicitly for the benefit
of Mortgagor shall be for the benefit of) the respective  successors and assigns
of Mortgagor,  and all persons  claiming under or through  Mortgagor or any such
successor  or assign,  and shall inure to the benefit of and be  enforceable  by
Mortgagee and its successors and assigns and any successor holders of any of the
Note at the  time  outstanding.  The  headings  and  table of  contents  in this
Mortgage are for  convenience of reference only and shall not limit or otherwise
affect any of the terms hereof.

                                       20



<PAGE>


                                                                   EXHIBIT 10.51

This Mortgage shall be construed and enforced in accordance with and governed by
the laws of the  State of  Wyoming,  without  giving  effect  to any  choice  or
conflict of law  provision,  either or the State of Wyoming or elsewhere,  which
would cause the application of any laws other than of the State of Wyoming.

        IN WITNESS  WHEREOF,  Mortgagor  has  caused  this  Mortgage  to be duly
executed as of the day and year first above written.

                                            KENNECOTT URANIUM COMPANY




                                            By:     /s/  L. R. Cardey-Yates
                                               --------------------------------
                                           Title:  Director/Assistant Secretary



Attest:    /s/   Shannon Crompton
        ------------------------------------
        Secretary

                                       21



<PAGE>


                                                                   EXHIBIT 10.51

STATE OF UTAH                )
                             : ss
COUNTY OF SALT LAKE          )

The foregoing  instrument was acknowledged before me by L. R. Cardey-Yates,  the
Director/Asst.  Secretary of Kennecott Uranium Company, a Delaware  corporation,
who acknowledged to me that Kennecott  Uranium Company executed the same on this
23rd day of June, 1997.

Witness my hand and official seal.

                                                   /s/ Colleen S. Jones
                                               --------------------------------
                                                      Notary Public

My Commission Expires:                             Residing at:

12-1-98                                            Salt Lake City, Utah





[Seal]


                                       22



<PAGE>


                                                                   EXHIBIT 10.51

                                          EXHIBIT A

            TO MORTGAGE, SECURITY AGREEMENT, FINANCING STATEMENT AND
            ASSIGNMENT OF PROCEEDS, RENTS AND LEASES AMONG KENNECOTT
            URANIUM COMPANY, MORTGAGOR AND KENNECOTT ENERGY COMPANY,
                                   MORTGAGEE.
                               SCHEDULE OF CLAIMS


This Exhibit is not filed with this Form 10-K for the year ended May 31, 1997.


                                       23



<PAGE>


                                                                   EXHIBIT 10.51

                                    EXHIBIT B

            TO MORTGAGE, SECURITY AGREEMENT, FINANCING STATEMENT AND
            ASSIGNMENT OF PROCEEDS, RENTS AND LEASES AMONG KENNECOTT
            URANIUM COMPANY, MORTGAGOR AND KENNECOTT ENERGY COMPANY,
                                   MORTGAGEE.


                     SCHEDULE OF IMPROVEMENTS AND EASEMENTS


This Exhibit is not filed with this Form 10-K for the year ended May 31, 1997.


                                       24



<PAGE>


                                                                   EXHIBIT 10.51

                                    EXHIBIT C

            TO MORTGAGE, SECURITY AGREEMENT, FINANCING STATEMENT AND
            ASSIGNMENT OF PROCEEDS, RENTS AND LEASES AMONG KENNECOTT
            URANIUM COMPANY, MORTGAGOR AND KENNECOTT ENERGY COMPANY,
                                   MORTGAGEE.


                            SCHEDULE OF WATER RIGHTS


This Exhibit is not filed with this Form 10-K for the year ended May 31, 1997.


                                       25



<PAGE>


                                                                   EXHIBIT 10.51

                                    EXHIBIT D

            TO MORTGAGE, SECURITY AGREEMENT, FINANCING STATEMENT AND
            ASSIGNMENT OF PROCEEDS, RENTS AND LEASES AMONG KENNECOTT
            URANIUM COMPANY, MORTGAGOR AND KENNECOTT ENERGY COMPANY,
                                   MORTGAGEE.


                              SCHEDULE OF EQUIPMENT


This Exhibit is not filed with this Form 10-K for the year ended May 31, 1997.


                                       26



<PAGE>


                                                                   EXHIBIT 10.51
                                    EXHIBIT E

            TO MORTGAGE, SECURITY AGREEMENT, FINANCING STATEMENT AND
            ASSIGNMENT OF PROCEEDS, RENTS AND LEASES AMONG KENNECOTT
            URANIUM COMPANY, MORTGAGOR AND KENNECOTT ENERGY COMPANY,
                                   MORTGAGEE.


                             SCHEDULE OF AGREEMENTS


This Exhibit is not filed with this Form 10-K for the year ended May 31, 1997.


                                       27