<PAGE>
                                                                     EXHIBIT 4.5
================================================================================






                              SUBSIDIARY GUARANTEE








                            Dated as of June 19, 2003

                                  Senior Notes


                                       of


                               NRP (OPERATING) LLC







================================================================================



<PAGE>

                                TABLE OF CONTENTS

                          (Not a part of the Agreement)

<TABLE>
<CAPTION>


SECTION                                                HEADING                                                 PAGE
<S>                        <C>                                                                                  <C>
Parties...........................................................................................................1

Recitals..........................................................................................................1

SECTION 1.                 DEFINITIONS............................................................................2


SECTION 2.                 GUARANTEE OF NOTES AND NOTE PURCHASE AGREEMENTS........................................2


SECTION 3.                 GUARANTEE OF PAYMENT AND PERFORMANCE...................................................2


SECTION 4.                 GENERAL PROVISIONS RELATING TO THE GUARANTEE...........................................3


SECTION 5.                 REPRESENTATIONS AND WARRANTIES OF THE GUARANTORS.......................................8


SECTION 6.                 GUARANTOR COVENANTS....................................................................9


SECTION 7.                 GOVERNING LAW.........................................................................10


SECTION 8.                 AMENDMENTS, WAIVERS AND CONSENTS......................................................10


SECTION 9.                 NOTICES...............................................................................11


SECTION 10.                MISCELLANEOUS.........................................................................11


SECTION 11.                INDEMNITY.............................................................................12


Signature........................................................................................................13

</TABLE>

                                      -i-


<PAGE>




                              SUBSIDIARY GUARANTEE

                 5.55% Senior Notes, Series A, due June 19, 2023
                 4.91% Senior Notes, Series B, due June 19, 2018
                 5.55% Senior Notes, Series C, due June 19, 2013

         This SUBSIDIARY GUARANTEE dated as of June 19, 2003 (the or this
"Guarantee") is entered into on a joint and several basis by the undersigned,
together with any entity which may become a party hereto by execution and
delivery of a Subsidiary Guarantee Supplement in substantially the form set
forth as EXHIBIT A hereto (a "Guarantee Supplement") (which parties are
hereinafter referred to individually as a "Guarantor" and collectively as the
"Guarantors").


                                    RECITALS

          A. Each Guarantor is a subsidiary or affiliate of NRP (OPERATING) LLC,
a Delaware limited liability company (the "Company").

          B. In order to reduce bank borrowing and for general limited liability
company purposes, the Company has entered into those certain separate Note
Purchase Agreements each dated as of June 19, 2003 (the "Note Purchase
Agreements") between the Company and each of the purchasers named on Schedule A
thereto (the "Initial Note Purchasers"; the Initial Note Purchasers, together
with their successors, assigns or any other future holder of the Notes (as
defined below), the "Holders"), providing for, inter alia, the issue and sale by
the Company to the Initial Note Purchasers of up to $175,000,000 aggregate
principal amount of its (i) 5.55% Senior Notes, Series A, due June 19, 2023,
(ii) 4.91% Senior Notes, Series B, due June 19, 2018 and (iii) 5.55% Senior
Notes, Series C, due June 19, 2013 (collectively, the "2003 Notes," and such
2003 Notes together with all other notes issued under the Note Purchase
Agreements, the "Notes").

          C. The Holders have required as a condition to their purchase of the
Notes that the Company cause the undersigned to enter into this Guarantee and
cause each entity that becomes a Subsidiary after June 19, 2003 to enter into a
Guarantee Supplement, in each case as security for the Notes, and the Company
has agreed to cause the undersigned to execute this Guarantee and to cause such
Subsidiaries to execute a Guarantee Supplement, in each case in order to induce
the Initial Note Purchasers to purchase the Notes and thereby benefit the
Company and its Subsidiaries by providing funds to reduce bank borrowing and for
general limited liability company purposes.

          D. Each of the Guarantors will derive substantial direct and indirect
benefit from the sale of the Notes to the Initial Note Purchasers.

          NOW, THEREFORE, as required by Section 4.11 of the Note Purchase
Agreements and in consideration of the premises and other good and valuable
consideration, the receipt and sufficiency whereof are hereby acknowledged, each
Guarantor does hereby covenant and agree, jointly and severally, as follows:

<PAGE>


SECTION 1.           DEFINITIONS.

         Capitalized terms used herein shall have the meanings set forth in the
Note Purchase Agreements unless herein defined or the context shall otherwise
require.

SECTION 2.           GUARANTEE OF NOTES AND NOTE PURCHASE AGREEMENTS.

         (a) Each Guarantor jointly and severally does hereby irrevocably,
absolutely and unconditionally guarantee unto the Holders: (1) the full and
prompt payment of the principal of, premium, if any, and interest on the Notes
from time to time outstanding, as and when such payments shall become due and
payable whether by lapse of time, upon redemption or prepayment, by extension or
by acceleration or declaration or otherwise (including (to the extent legally
enforceable) interest due on overdue payments of principal, premium, if any, or
interest at the rate set forth in the Notes) in Federal or other immediately
available funds of the United States of America which at the time of payment or
demand therefor shall be legal tender for the payment of public and private
debts, (2) the full and prompt performance and observance by the Company of each
and all of the obligations, covenants and agreements required to be performed or
owed by the Company under the terms of the Notes and the Note Purchase
Agreements and (3) the full and prompt payment, upon demand by any Holder of all
costs and expenses, legal or otherwise (including reasonable attorneys' fees),
if any, as shall have been expended or incurred in the enforcement of any
rights, privileges or liabilities in favor of the Holders under or in respect of
the Notes and the Note Purchase Agreements or under this Guarantee or in any
consultation or action in connection therewith or herewith.

         (b) The liability of each Guarantor under this Guarantee shall not
exceed an amount equal to a maximum amount as will, after giving effect to such
maximum amount and all other liabilities of such Guarantor, contingent or
otherwise, result in the obligations of such Guarantor hereunder not
constituting a fraudulent transfer, obligation or conveyance.

SECTION 3.           GUARANTEE OF PAYMENT AND PERFORMANCE.

         This is a guarantee of payment and performance and each Guarantor
hereby waives, to the fullest extent permitted by law, any right to require that
any action on or in respect of any Note or the Note Purchase Agreements be
brought against the Company or any other Person or that resort be had to any
direct or indirect security for the Note Purchase Agreements or any other
remedy. Any Holder may, at its option, proceed hereunder against any Guarantor
in the first instance to collect monies when due, the payment of which is
guaranteed hereby, without first proceeding against the Company or any other
Person and without first resorting to any direct or indirect security for the
Notes or for this Guarantee or any other remedy. The liability of each Guarantor
hereunder shall in no way be affected or impaired by any acceptance by any
Holder of any direct or indirect security for, or other guaranties of, any Debt,
liability or obligation of the Company or any other Person to any Holder or by
any failure, delay, neglect or omission by any Holder to realize upon or protect
any such guarantees, Debt, liability or obligation or any notes or other
instruments evidencing the same or any direct or indirect security therefor or
by any approval, consent, waiver, or other action taken, or omitted to be taken
by any such Holder.


                                      -2-

<PAGE>


         The covenants and agreements on the part of the Guarantors herein
contained shall take effect as joint and several covenants and agreements, and
references to the Guarantors shall take effect as references to each of them and
none of them shall be released from liability hereunder by reason of the
guarantee ceasing to be binding as a continuing security on any other of them.

SECTION 4.           GENERAL PROVISIONS RELATING TO THE GUARANTEE.

         (a) Each Guarantor hereby consents and agrees that any Holder or
Holders from time to time, with or without any further notice to or assent from
any other Guarantor may, without in any manner affecting the liability of any
Guarantor under this Guarantee, and upon such terms and conditions as any such
Holder or Holders may deem advisable:

                   (1) extend in whole or in part (by renewal or otherwise),
         modify, change, compromise, release or extend the duration of the time
         for the performance or payment of any Debt, liability or obligation of
         the Company or of any other Person secondarily or otherwise liable for
         any Debt, liability or obligations of the Company on the Notes, or
         waive any Default or Event of Default with respect thereto, or waive,
         modify, amend or change any provision of any other agreement or waive
         this Guarantee; or

                   (2) sell, release, surrender, modify, impair, exchange or
         substitute any and all property, of any nature and from whomsoever
         received, held by, or for the benefit of, any such Holder as direct or
         indirect security for the payment or performance of any Debt, liability
         or obligation of the Company or of any other Person secondarily or
         otherwise liable for any Debt, liability or obligation of the Company
         on the Notes; or

                   (3) settle, adjust or compromise any claim of the Company
         against any other Person secondarily or otherwise liable for any Debt,
         liability or obligation of the Company on the Notes.

         Each Guarantor hereby ratifies and confirms any such extension,
renewal, change, sale, release, waiver, surrender, exchange, modification,
amendment, impairment, substitution, settlement, adjustment or compromise and
that the same shall be binding upon it, and hereby waives, to the fullest extent
permitted by law, any and all defenses, counterclaims or offsets which it might
or could have by reason thereof, it being understood that such Guarantor shall
at all times be bound by this Guarantee and remain liable hereunder.

         (b) Each Guarantor hereby waives, to the fullest extent permitted by
law:

                   (1) notice of acceptance of this Guarantee by the Holders or
         of the creation, renewal or accrual of any liability of the Company,
         present or future, or of the reliance of such Holders upon this
         Guarantee (it being understood that every Debt, liability and
         obligation described in SECTION 2 hereof shall conclusively be presumed
         to have been created, contracted or incurred in reliance upon the
         execution of this Guarantee);


                                      -3-

<PAGE>


                   (2) demand of payment by any Holder from the Company or any
         other Person indebted in any manner on or for any of the Debt,
         liabilities or obligations hereby guaranteed; and

                   (3) presentment for the payment by any Holder or any other
         Person of the Notes or any other instrument, protest thereof and notice
         of its dishonor to any party thereto and to such Guarantor.

         The obligations of each Guarantor under this Guarantee and the rights
of any Holder to enforce such obligations by any proceedings, whether by action
at law, suit in equity or otherwise, shall not be subject to any reduction,
limitation, impairment or termination, whether by reason of any claim of any
character whatsoever or otherwise and shall not be subject to any defense,
set-off, counterclaim (other than any compulsory counterclaim), recoupment or
termination whatsoever.

         (c) The obligations of the Guarantors hereunder shall be binding upon
the Guarantors and their successors and assigns, and shall remain in full force
and effect irrespective of:

                   (1) the genuineness, validity, regularity or enforceability
         of the Notes or the Note Purchase Agreements or any of the terms of any
         thereof, the continuance of any obligation on the part of the Company
         or any other Person on or in respect of the Notes or under the Note
         Purchase Agreements or any other agreement or the power or authority or
         the lack of power or authority of the Company to issue the Notes or the
         Company to execute and deliver the Note Purchase Agreements or any
         other agreement or of any Guarantor to execute and deliver this
         Guarantee or to perform any of its obligations hereunder or the
         existence or continuance of the Company or any other Person as a legal
         entity; or

                   (2) any default, failure or delay, willful or otherwise, in
         the performance by the Company, any Guarantor or any other Person of
         any obligations of any kind or character whatsoever under the Notes,
         the Note Purchase Agreements, this Guarantee or any other agreement; or

                   (3) any creditors' rights, bankruptcy, receivership or other
         insolvency proceeding of the Company, any Guarantor or any other Person
         or in respect of the property of the Company, any Guarantor or any
         other Person or any merger, consolidation, reorganization, dissolution,
         liquidation, the sale of all or substantially all of the assets of or
         winding up of the Company, any Guarantor or any other Person; or

                   (4) impossibility or illegality of performance on the part of
         the Company, any Guarantor or any other Person of its obligations under
         the Notes, the Note Purchase Agreements, this Guarantee or any other
         agreements; or

                   (5) in respect of the Company or any other Person, any change
         of circumstances, whether or not foreseen or foreseeable, whether or
         not imputable to the Company or any other Person, or other
         impossibility of performance through fire,


                                      -4-

<PAGE>

         explosion, accident, labor disturbance, floods, droughts, embargoes,
         wars (whether or not declared), civil commotion, acts of God or the
         public enemy, delays or failure of suppliers or carriers, inability to
         obtain materials, action of any Federal or state regulatory body or
         agency, change of law or any other causes affecting performance, or
         any other force majeure, whether or not beyond the control of the
         Company or any other Person and whether or not of the kind
         hereinbefore specified; or

                   (6) any attachment, claim, demand, charge, Lien, order,
         process, encumbrance or any other happening or event or reason, similar
         or dissimilar to the foregoing, or any withholding or diminution at the
         source, by reason of any taxes, assessments, expenses, Debt,
         obligations or liabilities of any character, foreseen or unforeseen,
         and whether or not valid, incurred by or against the Company, any
         Guarantor or any other Person or any claims, demands, charges or Liens
         of any nature, foreseen or unforeseen, incurred by the Company, any
         Guarantor or any other Person, or against any sums payable in respect
         of the Notes or under the Note Purchase Agreements or this Guarantee,
         so that such sums would be rendered inadequate or would be unavailable
         to make the payments herein provided; or

                   (7) any order, judgment, decree, ruling or regulation
         (whether or not valid) of any court of any nation or of any political
         subdivision thereof or any body, agency, department, official or
         administrative or regulatory agency of any thereof or any other action,
         happening, event or reason whatsoever which shall delay, interfere
         with, hinder or prevent, or in any way adversely affect, the
         performance by the Company, any Guarantor or any other Person of its
         respective obligations under or in respect of the Notes, the Note
         Purchase Agreements, this Guarantee or any other agreement; or

                   (8) the failure of any Guarantor to receive any benefit from
         or as a result of its execution, delivery and performance of this
         Guarantee; or

                   (9) any failure or lack of diligence in collection or
         protection, failure in presentment or demand for payment, protest,
         notice of protest, notice of default and of nonpayment, any failure to
         give notice to any Guarantor of failure of the Company, any Guarantor
         or any other Person to keep and perform any obligation, covenant or
         agreement under the terms of the Notes, the Note Purchase Agreements,
         this Guarantee or any other agreement or failure to resort for payment
         to the Company, any Guarantor or to any other Person or to any other
         guaranty or to any property, security, Liens or other rights or
         remedies; or

                  (10) the acceptance of any additional security or other
         guaranty, the advance of additional money to the Company or any other
         Person, the renewal or extension of the Notes or amendments,
         modifications, consents or waivers with respect to the Notes, the Note
         Purchase Agreements or any other agreement, or the sale, release,
         substitution or exchange of any security for the Notes; or

                  (11) any merger or consolidation of the Company, any Guarantor
         or any other Person into or with any other Person or any sale, lease,
         transfer or other disposition of


                                      -5-

<PAGE>

         any of the assets of the Company, any Guarantor or any other Person to
         any other Person, or any change in the ownership of any shares or
         partnership interests of the Company, any Guarantor or any other
         Person; or

                  (12) any defense whatsoever that: (i) the Company or any other
         Person might have to the payment of the Notes (principal, premium, if
         any, or interest), other than payment thereof in Federal or other
         immediately available funds, or (ii) the Company or any other Person
         might have to the performance or observance of any of the provisions of
         the Notes, the Note Purchase Agreement or any other agreement, whether
         through the satisfaction or purported satisfaction by the Company or
         any other Person of its debts due to any cause such as bankruptcy,
         insolvency, receivership, merger, consolidation, reorganization,
         dissolution, liquidation, winding-up or otherwise, other than the
         defense of indefeasible payment in full in cash of the Notes; or

                  (13) any act or failure to act with regard to the Notes, the
         Note Purchase Agreements, this Guarantee or any other agreement or
         anything which might vary the risk of any Guarantor or any other
         Person; or

                  (14) any other circumstance which might otherwise constitute a
         defense available to, or a discharge of, any Guarantor or any other
         Person in respect of the obligations of any Guarantor or other Person
         under this Guarantee or any other agreement, other than the defense of
         indefeasible payment in full in cash of the Notes;

provided that the specific enumeration of the above-mentioned acts, failures or
omissions shall not be deemed to exclude any other acts, failures or omissions,
though not specifically mentioned above, it being the purpose and intent of this
Guarantee and the parties hereto that the obligations of each Guarantor shall be
absolute and unconditional and shall not be discharged, impaired or varied
except by the payment of the principal of, premium, if any, and interest on the
Notes in accordance with their respective terms whenever the same shall become
due and payable as in the Notes provided, at the place specified in and all in
the manner and with the effect provided in the Notes and the Note Purchase
Agreements, as each may be amended or modified from time to time. Without
limiting the foregoing, it is understood that repeated and successive demands
may be made and recoveries may be had hereunder as and when, from time to time,
the Company shall default under or in respect of the terms of the Notes or the
Note Purchase Agreements and that notwithstanding recovery hereunder for or in
respect of any given default or defaults by the Company under the Notes or the
Note Purchase Agreements, this Guarantee shall remain in full force and effect
and shall apply to each and every subsequent default.

         (d) All rights of any Holder may be transferred or assigned at any time
in accordance with the Note Purchase Agreements and shall be considered to be
transferred or assigned at any time or from time to time upon the transfer of
such Note in accordance with the Note Purchase Agreements whether with or
without the consent of or notice to the Guarantors under this Guarantee.

         (e) To the extent of any payments made under this Guarantee, the
Guarantors shall be subrogated to the rights of the Holder or Holders upon whose
Notes such payment was made, but


                                      -6-

<PAGE>

each Guarantor covenants and agrees that such right of subrogation shall be
junior and subordinate in right of payment to the prior indefeasible final
payment in cash in full of all amounts due and owing by the Company with respect
to the Notes and the Note Purchase Agreements and by the Guarantors under this
Guarantee, and the Guarantors shall not take any action to enforce such right of
subrogation, and the Guarantors shall not accept any payment in respect of such
right of subrogation, until all amounts due and owing by the Company under or in
respect of the Notes and the Note Purchase Agreements and all amounts due and
owing by the Guarantors hereunder have indefeasibly been paid in cash in full.
If any amount shall be paid to any Guarantor in violation of the preceding
sentence at any time prior to the indefeasible payment in cash in full of the
Notes and all other amounts payable under the Notes, the Note Purchase
Agreements and this Guarantee, such amount shall be held in trust for the
benefit of the Holders and shall forthwith be paid to the Holders to be credited
and applied to the amounts due or to become due with respect to the Notes and
all other amounts payable under the Note Purchase Agreements and this Guarantee,
whether matured or unmatured.

         (f) To the extent of any payments made under this Guarantee, each
Guarantor making such payment shall have a right of contribution from the other
Guarantors, but such Guarantor covenants and agrees that such right of
contribution shall be subordinate in right of payment to the rights of the
Holders for which full payment has not been made or provided for and, to that
end, such Guarantor agrees not to claim or enforce any such right of
contribution unless and until all of the Notes and all other sums due and
payable under the Note Purchase Agreements have been fully and irrevocably paid
and discharged.

         (g) Each Guarantor agrees that to the extent the Company or any other
Person makes any payment on any Note, which payment or any part thereof is
subsequently invalidated, voided, declared to be fraudulent or preferential, set
aside, recovered, rescinded or is required to be retained by or repaid to a
trustee, receiver, or any other Person under any bankruptcy code, common law, or
equitable cause, then and to the extent of such payment, the obligation or the
part thereof intended to be satisfied shall be revived and continued in full
force and effect with respect to the Guarantors' obligations hereunder, as if
said payment had not been made. The liability of the Guarantors hereunder shall
not be reduced or discharged, in whole or in part, by any payment to any Holder
from any source that is thereafter paid, returned or refunded in whole or in
part by reason of the assertion of a claim of any kind relating thereto,
including, but not limited to, any claim for breach of contract, breach of
warranty, preference, illegality, invalidity, or fraud asserted by any account
debtor or by any other Person.

         (h) No Holder shall be under any obligation: (1) to marshal any assets
in favor of the Guarantors or in payment of any or all of the liabilities of the
Company under or in respect of the Notes or the obligations of the Guarantors
hereunder or (2) to pursue any other remedy that the Guarantors may or may not
be able to pursue themselves and that may lighten the Guarantors' burden, any
right to which each Guarantor hereby expressly waives.


                                      -7-
<PAGE>

SECTION 5.           REPRESENTATIONS AND WARRANTIES OF THE GUARANTORS.

         Each Guarantor represents and warrants to each Holder that:

         (a) Such Guarantor is a corporation or other legal entity duly
organized, validly existing and in good standing under the laws of its
jurisdiction of organization, and is duly qualified as a foreign corporation or
other legal entity and is in good standing in each jurisdiction in which such
qualification is required by law, other than those jurisdictions as to which the
failure to be so qualified or in good standing would not, individually or in the
aggregate, reasonably be expected to have a material adverse effect on (1) the
business, operations, affairs, financial condition, assets or properties of the
Company and its subsidiaries, taken as a whole, or (2) the ability of such
Guarantor to perform its obligations under this Guarantee, or (3) the validity
or enforceability of this Guarantee (herein in this SECTION 5, a "Material
Adverse Effect"). Such Guarantor has the power and authority to own or hold
under lease the properties it purports to own or hold under lease, to transact
the business it transacts and proposes to transact, to execute and deliver this
Guarantee and to perform the provisions hereof.

         (b) This Guarantee has been duly authorized by all necessary action on
the part of such Guarantor, and this Guarantee constitutes a legal, valid and
binding obligation of such Guarantor enforceable against such Guarantor in
accordance with its terms, except as such enforceability may be limited by (1)
applicable bankruptcy, insolvency, reorganization, moratorium or other similar
laws affecting the enforcement of creditors' rights generally and (2) general
principles of equity (regardless of whether such enforceability is considered in
a proceeding in equity or at law).

         (c) The execution, delivery and performance by such Guarantor of this
Guarantee will not (1) contravene, result in any breach of, or constitute a
default under, or result in the creation of any Lien in respect of any property
of such Guarantor or any of its Subsidiaries under any indenture, mortgage, deed
of trust, loan, purchase or credit agreement, lease, charter document or by-law,
or any other agreement or instrument to which such Guarantor or any of its
Subsidiaries is bound or by which such Guarantor or any of its Subsidiaries or
any of their respective properties may be bound or affected, (2) conflict with
or result in a breach of any of the terms, conditions or provisions of any
order, judgment, decree, or ruling of any court, arbitrator or governmental
authority applicable to such Guarantor or any of its Subsidiaries or (3) violate
any provision of any statute or other rule or regulation of any Governmental
Authority applicable to the such Guarantor or any of its Subsidiaries.

         (d) No consent, approval or authorization of, or registration, filing
or declaration with, any governmental authority is required in connection with
the execution, delivery or performance by such Guarantor of this Guarantee.

         (e) Such Guarantor is solvent, has capital not unreasonably small in
relation to its business or any contemplated or undertaken transaction and has
assets having a value both at fair valuation and at present fair salable value
greater than the amount required to pay its debts as they become due and greater
than the amount that will be required to pay its probable liability on its
existing debts as they become absolute and matured. Such Guarantor does not
intend to incur


                                      -8-
<PAGE>

debts beyond its ability to pay such debts as they become due. Such Guarantor
will not be rendered insolvent by the execution and delivery of, this Guarantee
and, on a consolidated basis with the Company, will not be rendered insolvent.
Such Guarantor does not intend to hinder, delay or defraud its creditors by or
through the execution and delivery of, or performance of its obligations under,
this Guarantee.

         (f) Each representation contained in Section 5 of the Note Purchase
Agreements is true and correct to the extent applicable to such Guarantor.

SECTION 6.           GUARANTOR COVENANTS.

         (a) Each Guarantor agrees to comply with the terms and provisions of
Sections 9 and 10 of the Note Purchase Agreements, insofar as such provisions
apply to such Guarantor, as if said Sections were set forth herein in full.

         (b) In addition to the foregoing, no Guarantor shall consolidate with
or merge with any other corporation, limited liability company or limited
partnership (other than the Company or another Guarantor) or convey, transfer or
lease substantially all of its assets in a single transaction or series of
transactions to any Person unless:

                   (i) the successor formed by such consolidation or the
         survivor of such merger or the Person that acquires by conveyance,
         transfer or lease substantially all of the assets of such Guarantor as
         an entirety, as the case may be, shall be a solvent corporation,
         limited liability company or limited partnership organized and existing
         under the laws of the United States or any State thereof (including the
         District of Columbia), and, if such Guarantor is not such corporation,
         limited liability company or limited partnership (i) such corporation,
         limited liability company or limited partnership shall have executed
         and delivered to each holder of any Notes its assumption of the due and
         punctual performance and observance of each covenant and condition of
         this Guarantee and (ii) shall have caused to be delivered to each
         holder of any Notes an opinion of nationally recognized independent
         counsel, or other independent counsel reasonably satisfactory to the
         Required Holders, to the effect that all agreements or instruments
         effecting such assumption are enforceable in accordance with their
         terms and comply with the terms hereof;

                  (ii) immediately after giving effect to such transaction, (A)
         no Default or Event of Default shall have occurred and be continuing;
         and (B) the Company would be able to incur at least $1.00 of additional
         Debt under the terms of Section 10.6(a)(iii) of the Note Purchase
         Agreement.

No such conveyance, transfer or lease of substantially all of the assets of a
Guarantor shall have the effect of releasing such Guarantor or any successor
corporation, limited liability company or limited partnership that shall
theretofore have become such in the manner prescribed in this Section 6 from its
liability under this Guarantee.


                                      -9-

<PAGE>


SECTION 7.           GOVERNING LAW.

         (a) THIS GUARANTEE SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE
WITH THE LAWS OF THE STATE OF NEW YORK APPLICABLE THEREIN.

         (b) Each Guarantor hereby (i) irrevocably submits and consents to the
jurisdiction of the federal court located in New York (or, if such court lacks
jurisdiction, the State courts located therein), and irrevocably agrees that all
actions or proceedings relating to this Guarantee may be litigated in such
courts, and (ii) waives any objection which it may have based on improper venue
or forum non conveniens to the conduct of any proceeding in any such court and
waives personal service of any and all process upon it, and (iii) consents that
all such service of process be made by delivery to it at the address of such
Person set forth in SECTION 9 below. Nothing contained in this section shall
affect the right of any Holder to serve legal process in any other manner
permitted by law or to bring any action or proceeding in the courts of any
jurisdiction against a Guarantor or to enforce a judgment obtained in the courts
of any other jurisdiction.

         (c) THE PARTIES HERETO WAIVE ANY RIGHT TO HAVE A JURY PARTICIPATE IN
RESOLVING ANY DISPUTE, WHETHER SOUNDING IN CONTRACT, TORT, OR OTHERWISE, BETWEEN
THEM ARISING OUT OF, CONNECTED WITH, RELATED TO OR INCIDENTAL TO THE
RELATIONSHIP ESTABLISHED BETWEEN THEM IN CONNECTION WITH THIS GUARANTEE, THE
NOTES, THE NOTE PURCHASE AGREEMENTS OR ANY OTHER INSTRUMENT, DOCUMENT OR
AGREEMENT EXECUTED OR DELIVERED IN CONNECTION HEREWITH OR THE TRANSACTIONS
RELATED HERETO. THE PARTIES HERETO HEREBY AGREE AND CONSENT THAT ANY SUCH CLAIM,
DEMAND, ACTION OR CAUSE OF ACTION SHALL BE DECIDED BY COURT TRIAL WITHOUT A JURY
AND THAT ANY OF THEM MAY FILE AN ORIGINAL COUNTERPART OR A COPY OF THIS
GUARANTEE WITH ANY COURT AS WRITTEN EVIDENCE OF THE CONSENT OF THE PARTIES
HERETO TO THE WAIVER OF THEIR RIGHT TO TRIAL BY JURY.

SECTION 8.           AMENDMENTS, WAIVERS AND CONSENTS.

         (a) This Guarantee may be amended, and the observance of any term
hereof may be waived (either retroactively or prospectively), with (and only
with) the written consent of each Guarantor and the Holders.

         (b) The Guarantors will provide each Holder (irrespective of the amount
of Notes then owned by it) with sufficient information, sufficiently far in
advance of the date a decision is required, to enable such Holder to make an
informed and considered decision with respect to any proposed amendment, waiver
or consent in respect of any of the provisions hereof. The Guarantors will
deliver executed or true and correct copies of each amendment, waiver or consent
effected pursuant to the provisions of this SECTION 8 to each Holder promptly
following the date on which it is executed and delivered by, or receives the
consent or approval of, the Required Holders.

         (c) The Company will not directly or indirectly pay or cause to be paid
any remuneration, whether by way of fee or otherwise, or grant any security, to
any Holder as consideration for or as an inducement to the entering into by any
Holder of any waiver or amendment of any of the terms and provisions hereof
unless such remuneration is concurrently


                                      -10-

<PAGE>


paid, or security is concurrently granted, on the same terms, ratably to each
Holder even if such Holder did not consent to such waiver or amendment.

         (d) Any amendment or waiver consented to as provided in this SECTION 8
applies equally to all Holders and is binding upon them and upon each future
holder and upon the Guarantors. No such amendment or waiver will extend to or
affect any obligation, covenant or agreement not expressly amended or waived or
impair any right consequent thereon. No course of dealing between the Guarantors
and any Holder nor any delay in exercising any rights hereunder shall operate as
a waiver of any rights of any Holder. As used herein, the term "this Guarantee"
and references thereto shall mean this Guarantee as it may from time to time be
amended or supplemented.

         (e) Solely for the purpose of determining whether the Holders of the
requisite percentage of the aggregate principal amount of Notes then outstanding
approved or consented to any amendment, waiver or consent to be given under this
Guarantee, Notes directly or indirectly owned by any Guarantor, the Company or
any of their respective subsidiaries or Affiliates shall be deemed not to be
outstanding.

SECTION 9.           NOTICES.

         All notices and communications provided for hereunder shall be in
writing and sent (a) by telefacsimile if the sender on the same day sends a
confirming copy of such notice by a recognized overnight delivery service
(charges prepaid), or (b) by registered or certified mail with return receipt
requested (postage prepaid), or (c) by a recognized overnight delivery service
(with charges prepaid). Any such notice must be sent:

                   (1) if to any Holder or such Holder's nominee, to such Holder
         or such Holder's nominee at the address specified for such
         communications in Schedule A to the Note Purchase Agreements, or at
         such other address as such Holder or such Holder's nominee shall have
         specified to the Company in writing,

                   (2) if to any Guarantor, to such Guarantor c/o NRP
         (Operating) LLC at its address set forth at the beginning of the Note
         Purchase Agreement to the attention of Dwight Dunlap, Chief Financial
         Officer, or at such other address as such Guarantor shall have
         specified to the Holders in writing.

Notices under this SECTION 9 will be deemed given only when actually received.

SECTION 10.          MISCELLANEOUS.

         (a) No remedy herein conferred upon or reserved to any Holder is
intended to be exclusive of any other available remedy or remedies, but each and
every such remedy shall be cumulative and shall be in addition to every other
remedy given under this Guarantee now or hereafter existing at law or in equity.
No delay or omission to exercise any right or power accruing upon any default,
omission or failure of performance hereunder shall impair any such right or
power or shall be construed to be a waiver thereof but any such right or power
may be


                                      -11-

<PAGE>

exercised from time to time and as often as may be deemed expedient. In order to
entitle any Holder to exercise any remedy reserved to it under this Guarantee,
it shall not be necessary for such Holder to physically produce its Note in any
proceedings instituted by it or to give any notice, other than such notice as
may be herein expressly required.

         (b) The Guarantors will pay all sums becoming due under this Guarantee
by the method and at the address specified in the Note Purchase Agreements, or
by such other method or at such other address as any Holder shall have from time
to time specified to the Guarantors in writing for such purpose, without the
presentation or surrender of this Guarantee or any Note.

         (c) Any provision of this Guarantee that is prohibited or unenforceable
in any jurisdiction shall, as to such jurisdiction, be ineffective to the extent
of such prohibition or unenforceability without invalidating the remaining
provisions hereof, and any such prohibition or unenforceability in any
jurisdiction shall (to the full extent permitted by law) not invalidate or
render unenforceable such provision in any other jurisdiction.

         (d) If the whole or any part of this Guarantee shall be now or
hereafter become unenforceable against any one or more of the Guarantors for any
reason whatsoever or if it is not executed by any one or more of the Guarantors,
this Guarantee shall nevertheless be and remain fully binding upon and
enforceable against each other Guarantor as if it had been made and delivered
only by such other Guarantors.

         (e) This Guarantee shall be binding upon each Guarantor and its
successors and assigns and shall inure to the benefit of each Holder and its
successors and assigns so long as its Notes remain outstanding and unpaid.

         (f) This Guarantee may be executed in any number of counterparts, each
of which shall be an original but all of which together shall constitute one
instrument. Each counterpart may consist of a number of copies hereof, each
signed by less than all, but together signed by all, of the parties hereto.

SECTION 11.          INDEMNITY.

         To the fullest extent of applicable law, each Guarantor shall indemnify
and save each Holder harmless from and against any losses (other than any such
losses created as a result of the gross negligence or willful misconduct of any
Holder) which may arise by virtue of any of the obligations hereby guaranteed
being or becoming for any reason whatsoever in whole or in part void, voidable,
contrary to law, invalid, ineffective or otherwise unenforceable by the Holder
or any of them in accordance with its terms (all of the foregoing collectively,
an "Indemnifiable Circumstance"). For greater certainty, these losses shall
include without limitation all obligations hereby guaranteed which would have
been payable by the Company but for the existence of an Indemnifiable
Circumstance; provided, however, that the extent of the Guarantor's aggregate
liability under this SECTION 11 shall not at any time exceed the amount (but for
any Indemnifiable Circumstance) otherwise guaranteed pursuant to SECTION 2.


                                      -12-


<PAGE>



         IN WITNESS WHEREOF, the undersigned has caused this Guarantee to be
duly executed by an authorized representative as of this 19th day of June, 2003.



                              ACIN LLC
                              WPP LLC
                              GNP LLC
                              NNG LLC
                              CSTL LLC
                              WBRD LLC



                              By: NRP (Operating) LLC, as sole member



                              By: /s/ Dwight L. Dunlap
                                  ----------------------------------------------
                                  Name:  Dwight L. Dunlap
                                  Title: Chief Financial Officer and Treasurer


                                      -13-