<PAGE>   1
                                                                   EXHIBIT 10.80


                                PLEDGE AGREEMENT


         THIS PLEDGE AGREEMENT ("Agreement") entered into this 29th day of July,
1999, by and between Kean Argovitz Resorts-Shingle Springs, L.L.C., a Nevada
limited liability company ("Pledgor"), in favor of Lakes Shingle Springs, Inc.,
a Minnesota corporation ("Pledgee").


                              W I T N E S S E T H:


         WHEREAS, Pledgor has executed a promissory note in the original
principal amount of $970,000.00 (the "Note") in favor of Pledgee;

         WHEREAS, Pledgor has agreed to secure the Note by pledging and granting
a security interest in the Pledgor's Ownership Interest in Lakes KAR-Shingle
Springs, L.L.C., a Delaware limited liability company (the "Company");

         WHEREAS, Pledgor has agreed to assign its rights to receive certain
distributions from the Company in respect to Pledgor's Ownership Interest
pursuant to the terms of a Letter Agreement, dated of even date herewith, among
Pledgor and Pledgee (the "Letter Agreement").

         NOW, THEREFORE, in consideration of the foregoing and other good and
valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, Pledgor and Pledgee agree as follows: All capitalized terms not
otherwise defined herein shall have the respective meanings ascribed to them in
the Letter Agreement.

         1.  Pledge.

         1.1 As security for the prompt and complete payment and performance of
the obligations of Pledgor under the Note and this Agreement (the
"Liabilities"), Pledgor hereby delivers, pledges and grants a security interest
to Pledgee in the following:

                  (a)      All Ownership Interests in the Company now or
                           hereafter acquired by Pledgor, and all certificates
                           or other indicia of ownership representing such
                           Ownership Interests referred to together with all
                           rights to the proceeds thereof as the "Units";

                  (b)      All dividends and other distributions received by
                           Pledgor in accordance with Section 6 hereof; and

                  (c)      All "Proceeds", as such term is defined in the
                           Uniform Commercial Code as the same may from
                           time-to-time be in effect in the State of California

<PAGE>   2

                           (the "Code").

         The Units, powers and Proceeds thereof, together with the Property and
interests in Property described in Section 6 below, are hereinafter collectively
referred to as the "Collateral". Pledgor hereby appoints Pledgee its
attorney-in-fact to arrange at Pledgee's option for the transfer upon or at any
time after the existence or occurrence of an "Event of Default" of the
Collateral on the books of the Company to the name of Pledgee or to the name of
Pledgee's nominee. For purposes of this Agreement, an "Event of Default" shall
mean any failure of Pledgor to perform, comply with or observe any material
obligation, covenant or agreement under the Note or of Pledgor to perform,
comply with or observe any obligation, covenant or agreement under this
Agreement.

         2.  Voting Rights.

         2.1 During the term of this Pledge Agreement, and so long as there
shall not occur or exist an Event of Default, Pledgor shall have the right to
vote the Units on all Company questions; provided, however, that no action shall
be taken that would impair the value of the Collateral or be inconsistent with
or violate any provision of this Pledge Agreement or the Note. Upon the
existence or occurrence of an Event of Default, Pledgee shall thereafter be
entitled to exercise all voting powers pertaining to the Collateral.

         3.  Representations.

         3.1 Pledgor represents, warrants and agrees as follows:

                  (a)      Pledgor holds Ownership Interests in the Company,
                           representing 50.0% of all the outstanding Ownership
                           Interests in the Company;

                  (b)      Pledgor has full power and authority to enter into
                           this Pledge Agreement;

                  (c)      Pledgor has the right to vote, pledge and grant a
                           security interest in or otherwise transfer such
                           Collateral free of any liens, claims and
                           encumbrances; and

                  (d)      The Powers are duly executed and give the legal
                           holder thereof the authority they purport to confer.

         4. Limitation on Liens and Dispositions.

         4.1 Except for the lien created under this Pledge Agreement, Pledgor
agrees that it will not create, permit or suffer to exist, and will defend the
Collateral against and take such other action as is necessary to remove, any
lien, encumbrance, charge or right (a "Lien") on or against the Collateral and
will defend the right, title and interest of Pledgee in and to any of Pledgor's
right, title and interest in and to the Collateral against the claims and
demands of all

<PAGE>   3

other Persons. Except for the lien created under this Pledge Agreement, Pledgor
will not sell, assign, exchange, grant a security interest in, transfer,
encumber, or otherwise dispose of, any of the Collateral, or attempt or contract
to do so.

         5.  Subsequent Changes Affecting Collateral.

         5.1 Pledgor represents to Pledgee that Pledgor has made its own
arrangements for keeping informed of changes or potential changes affecting the
Collateral, and Pledgor agrees that, except as may be provided in any other
agreement between the parties, Pledgee shall not have any responsibility or
liability for informing Pledgor of any such changes or potential changes or for
taking any action or omitting to take any action with respect thereto. Pledgee
may, upon or at any time after the occurrence of an Event of Default, without
notice and at its option, transfer or register the Collateral or any part
thereof into its or its nominee's name with or without any indication that such
Collateral is subject to the security interest hereunder.

         6.  Distributions.

         6.1 If at any time this Pledge Agreement is effective, Pledgor, by
reason of its ownership of the Units, shall become entitled to receive, or shall
receive, any Ownership Interest (including, without limitation, any Ownership
Interest from any reclassification, increase or reduction of capital, or
reorganization), option, warrant, or other rights, whether as an addition to, in
substitution of, or in exchange for any Units, whether by declared dividend,
stock split, or other method, Pledgor agrees it shall accept the same as
Pledgee's agent and hold the same in trust for Pledgee and deliver the same
forthwith to Pledgee in the exact form received, with the endorsement of Pledgor
when requested by Pledgee and/or appropriate undated stock powers duly executed
in blank, to be held by Pledgee as additional collateral security for the
Liabilities.

         Any sums or property paid upon or in respect of the Units or any other
securities received under this section upon the reorganization, liquidation
(whether complete or partial), or dissolution of the issuer of any of the Units
or any such other securities shall immediately be paid over to Pledgee to be
held by Pledgee as additional collateral security for the Liabilities. All sums
of money and property so paid or distributed in respect of the Units, upon the
reorganization, liquidation or dissolution of the issuer of the Units, which are
received by Pledgor shall, until paid or delivered to Pledgee, be segregated
from the other property of funds of Pledgor and held by Pledgor in trust as
additional collateral security of the Liabilities.

         6.2 Except as provided in the Letter Agreement, Pledgor shall be
entitled to receive all cash dividends or distributions declared and paid with
respect to any Units, free of any security interest in favor of Pledgee
hereunder, provided that no uncured Event of Default exists at the time of such
dividend or distribution or will exist as a result of such dividend or
distribution. To the extent provided in the Letter Agreement, or upon the
occurrence and continuance of any Event of Default, Pledgee shall be entitled to
receive any and all such cash dividends or distributions, and Pledgor shall
immediately deliver to Pledgee any such cash dividends or distributions which it
receives.

<PAGE>   4

         7.  Power of Attorney.

         7.1 Pledgor does hereby irrevocably constitute and appoint Pledgee its
true and lawful attorney, with full power of substitution, for them and in their
name, place and stead, to ask, demand, collect, receive, receipt for, sue for,
compound and give acquittance for any and all sums or properties which may be or
become due, payable or distributable on or in respect of the Collateral or which
constitute a part thereof, with full power to settle, adjust or compromise any
claim thereunder or therefor as fully as Pledgor could themselves do, and to
endorse or sign the names of Pledgor on all commercial paper given in payment or
in part payment thereof and on all documents of satisfaction, discharge or
receipt required or requested in connection therewith, and in its discretion, to
file any claim or take any other action or proceeding, either in its own name or
in the names of Pledgor, or otherwise, which Pledgee may deem necessary or
appropriate to collect or otherwise realize upon any and all of the Collateral,
or effect a transfer thereof, or which may be necessary or appropriate to
protect and preserve the right, title and interest of Pledgee in and to such
Collateral and the security intended to be afforded hereby. Pledgee shall not
exercise its rights under this Section 7 unless and until there exists an Event
of Default and all applicable cure periods have expired.

         8.  Remedies.

         8.1 Upon the occurrence or existence of an Event of Default, which
remains uncured after the expiration of any applicable cure period, Pledgee
shall have, in addition to any other rights given by law or hereunder, all of
the rights and remedies with respect to the Collateral of a secured party under
the Uniform Commercial Code in effect in the State of California.

         8.2 Pledgor shall have thirty (30) days after written notice of an
Event of Default to cure such Default. Pledgee will give Pledgor reasonable
notice of the time and place of any public sale thereof, or of the time after
which any private sale or other intended disposition is to be made. Any sale of
the Collateral conducted in conformity with reasonable commercial practices of
banks, commercial finance companies, insurance companies or other financial
institution disposing of property similar to the Collateral shall be deemed to
be commercially reasonable. Notwithstanding any provisions to be contrary
contained herein any requirements of reasonable notice of such sale shall be met
if such notice is received by Pledgor as provided in Section 17 below, at least
five (5) days before the time of the sale or disposition. Any other requirement
of notice, demand or advertisement for sale is, to the extent permitted by law,
waived.

         8.3 In view of the fact that federal and state security laws may impose
certain restrictions on the method by which a sale of the Collateral may be
effected after an Event of Default, Pledgor agrees that, upon the occurrence or
existence of an Event of Default, Pledgee may, from time-to-time, attempt to
sell all or any part of the Collateral by means of a private placement
qualifying the bidder and prospective purchasers to those who will represent and
agree that they are purchasing for investment only and not for distribution. In
so doing, Pledgee may

<PAGE>   5

solicit offers to buy the Collateral, or any part of it, for cash, from a
limited number of investors deemed by Pledgee, in its reasonable judgment, to be
acceptable parties who might be interested in purchasing the Collateral, and if
Pledgee solicits such offers from not less than two (2) such investors, then the
acceptance by Pledgee of the highest offer obtained therefrom shall be deemed to
be a commercially reasonable method of disposition of such Collateral.

         8.4 Notwithstanding anything to the contrary in this Pledge Agreement,
any transfer of the Units will be subject to licensing and other regulatory
review and approval requirements and procedures of any Regulatory Authority (as
defined in Section 13.8 of the Operating Agreement of the Company).

         9. Waivers and Consents.

         9.1 Upon the occurrence or existence of an Event of Default, and after
the expiration of any applicable cure period, Pledgee may enforce this Pledge
Agreement independently of any other remedy or security Pledgee at any time may
have or hold in connection with the Liabilities, and it shall not be necessary
for Pledgee to marshal assets in favor of Pledgor or any other person or entity
or to proceed upon or against and/or exhaust any other security or remedy before
proceeding to enforce this Pledge Agreement. Pledgor expressly waives any right
to required Pledgee to marshal assets in favor of Pledgor or any other person or
entity or to proceed against any other person or entity or any Collateral
provided by any other person or entity, and agrees that Pledgee may proceed
against the Collateral in such order as it shall determine in its sole and
absolute discretion. Pledgor expressly waives the benefit of any statute(s) of
limitations affecting its liability hereunder or the enforcement of the
Liabilities, or any Liens created or granted herein. Pledgee's rights hereunder
shall be required to be restored or returned by Pledgee (whether as a "voidable
preference", "fraudulent conveyance" or otherwise) upon the bankruptcy,
insolvency or reorganization of Pledgor, or otherwise, all as though such amount
had not been paid. Pledgor expressly waives any and all of the following
defenses now or hereafter arising or asserted by reason of (a) any failure of
Pledgee to marshal assets in favor of Pledgor or any other person or entity
(except Pledgor) in connection with any sale or disposition of Collateral, (b)
any failure of Pledgee to give notice of sale or other disposition of Collateral
to any person or entity (except Pledgor), (c) any failure of Pledgee to file or
enforce a claim in any bankruptcy or other proceeding with respect to any person
or entity, (d) the election by Pledgee, in any bankruptcy proceeding of any
person or entity of the application or non-application of Section 1111(b) (2) of
the United States Bankruptcy Code, (e) any extension of credit or the grant of
any Lien under Section 364 of the United States Bankruptcy Code, (f) any
agreement or stipulation with respect to the provision of adequate protection in
any bankruptcy proceeding of any person or entity, (g) any bankruptcy,
insolvency, reorganization, arrangement, readjustment of debt, liquidation or
dissolution proceeding commenced by or against any person or entirety, including
any discharge of, or bar or stay against collecting, all or any of the
Liabilities (or any interest thereon) in or as a result of any such proceeding,
or (h) any action taken by Pledgee that is authorized by this Section 9 or any
other provision of this Pledge Agreement or the Note.

         10. Understanding With Respect to Waivers and Consents.

<PAGE>   6

         10.1 Pledgor warrants and agrees that each of the waivers and consents
set forth herein are made after consultation with legal counsel and with full
knowledge of their significance and consequences, with the understanding that
events giving rise to any defense or right waived may diminish, destroy or
otherwise adversely affect rights which Pledgor otherwise may have against
Pledgee or others or against the Collateral, and that, under the circumstances,
the waivers and consents herein given are reasonable and not contrary to public
policy or law. Such waivers and consents shall be effective to the maximum
extent permitted by law.

         11. Term.

         11.1 This Pledge Agreement shall remain in full force and effect until
all the Liabilities have been fully paid and satisfied. This Pledge Agreement
shall remain in full force and effect and continue to be effective should any
petition be filed by or against Pledgor for liquidation or reorganization,
should Pledgor become insolvent or make an assignment for the benefit of
creditors or should a receiver or trustee be appointed for all or any
significant part of Pledgor's assets, and shall continue to be effective or be
reinstated, as the case may be, if any time payment and performance of the
Liabilities, or any part thereof, is, pursuant to applicable law, rescinded or
reduced in amount or must otherwise be restored or returned by any obligee of
the Liabilities, whether as a "voidable preference," "fraudulent conveyance," or
otherwise, all as though such payment or performance had not been made. In the
event that any payment, or any part thereof, is rescinded, reduced, restored or
returned, the Liabilities shall be reinstated and deemed reduced only by such
amount paid and not so rescinded, reduced, restored or returned. Upon the
termination of the Pledge Agreement as provided above (other than as a result of
the sale of the Collateral), Pledgee will promptly release the security interest
and Lien created hereunder and will deliver the Collateral to Pledgor.

         12. Terms.

         12.1 The singular shall include plural and vice versa and any gender
shall include any other gender as the text shall indicate.

         13. Successor and Assigns.

         13.1 This Pledge Agreement shall be binding upon and inure to the
benefit of Pledgor, Pledgee and their respective successor and assigns.
Pledgor's successors and assigns shall include, without limitation, a receiver,
trustee to debtor in possession of or for the Pledgor. Without limiting the
generality of the foregoing, Pledgee may assign or otherwise transfer its rights
to receive payment or performance of the Liabilities (or any part thereof) to
any other person or entity, and such other person or entity shall thereupon
become vested with all of the rights in respect thereof granted to Pledgee
herein or otherwise.

         14. Applicable Law.

<PAGE>   7

         14.1 This Pledge Agreement shall be governed by and construed under the
internal laws (as opposed to conflict of laws provisions) of the State of
California. Whenever possible, each provision of this Pledge Agreement shall be
interpreted in such manner as to be effective and valid under applicable law,
but, if any provision of this Pledge Agreement shall be held to be prohibited by
or invalid under applicable law, such provision shall be ineffective only to the
extent of such prohibition or invalidity, without invalidating the remainder of
such provision or the remaining provisions of this Pledge Agreement.

         15. Further Assurances.

         15.1 Pledgor agrees that it will cooperate with Pledgee and will
execute and deliver, or cause to be executed and delivered, all such other
necessary stock powers, proxies, instruments and documents, and will take all
such other necessary action, including, without limitation, the filing of
financing statements, as Pledgee may reasonably request from time-to-time in
order to carry out the provisions and purposes hereof.

         16. Obligation.

         16.1 Pledgee shall be under no obligation to take any steps necessary
to preserve rights in the Collateral against any other parties but may do so at
its option, and all expenses incurred in connection therewith shall be for the
sole account of Pledgor.

         17. Notices.

         17.1 All notices and other communications provided for hereunder shall
be in writing (including telegraphic communication) and mailed or telegraphed,
telecopied or delivered,

         if to Pledgor, at:

                  Kean Argovitz Resorts-Shingle Springs, L.L.C.
                  11999 Katy Freeway, Suite 322
                  Houston, Texas 77079


         with a copy to:

                  Darryl M. Burman, Esq.
                  DiCecco, Fant & Burman, L.L.P.
                  1900 West Loop South, Suite 1100
                  Houston. Texas 77027

<PAGE>   8

         if to Pledgee, at:

                  Lakes Shingle Springs, Inc.
                  130 Cheshire Lane
                  Minnetonka, Minnesota 55305
                  Att.: Lyle Berman

         with a copy to:

                  Doug Twait, Esq.
                  Johnson Hamilton Quigley Twait, & Foley PLC
                  West 1450 First National Bank Building
                           332 Minnesota Street
                        Saint Paul, Minnesota 55101

or as to each party, at such other address as designated by such party in a
written notice to the other party. All notices shall be in writing and shall be
deemed to be validly served, given or delivered (i) three (3) days following
deposit in the United States mail, with proper postage prepaid; (ii) upon
delivery thereof if delivered by hand to the party to be notified as set forth
above; or (iii) upon acknowledgment of receipt thereof if transmitted to a valid
telecopier number for the party to be notified as set forth above.

         18. Section Headings.

         18.1 The section headings herein are for convenience of reference only,
and shall not affect in any way the interpretation of any of the provisions
hereof.




          IN WITNESS WHEREOF, Pledgor has executed and delivered this Pledge
Agreement as of the date first written above.

                                         Pledgor:

<PAGE>   9

                                         Kean Argovitz Resorts-Shingle Springs,
                                         L.L.C.


                                         By: /s/ Kevin M. Kean
                                             ----------------------------------
                                         Name:   Kevin M. Kean
                                              ---------------------------------
                                         Title: President
                                               --------------------------------




AGREED TO AND ACCEPTED BY:

Lakes Shingle Springs, Inc.


By: /s/ Timothy Cope
   ----------------------------
Name:   Timothy Cope
     --------------------------
Title: Executive Vice President
      -------------------------