AMERISTAR CASINOS, INC. Company CACTUS PETES, INC. AMERISTAR CASINO VICKSBURG, INC. AMERISTAR CASINO COUNCIL BLUFFS, INC. AMERISTAR CASINO LAS VEGAS, INC. AMERISTAR CASINOS FINANCING CORP. AMERISTAR CASINO ST. LOUIS, INC. AMERISTAR CASINO KANSAS CITY, INC. AMERISTAR CASINO ST. CHARLES, INC. AMERISTAR CASINO BLACK HAWK, INC. AMERISTAR EAST CHICAGO HOLDINGS, LLC AMERISTAR CASINO EAST CHICAGO, LLC AMERISTAR CASINO SPRINGFIELD, LLC AMERISTAR LAKE CHARLES HOLDINGS, LLC AMERISTAR CASINO LAKE CHARLES, LLC Guarantors WILMINGTON TRUST, NATIONAL ASSOCIATION (as successor by merger to Wilmington Trust FSB) Trustee FOURTH SUPPLEMENTAL INDENTURE Dated as of April 2, 2013 to Indenture Dated as of April 14, 2011 7.50% SENIOR NOTES DUE 2021

Section 1.02 Waiver of Compliance with Certain Covenants.

The Holders expressly waive compliance with any covenant (other than with respect to the due and punctual payment of the principal of, and premium, if any, and interest on all of the Notes) that would be violated as a result of the consummation of the Alternative Merger, the Post-Effective Merger and the other transactions contemplated by the Merger Agreement or otherwise required to effect the Alternative Merger and the Post-Effective Merger, including any covenant that would be violated by (i) the payment of the Merger consideration payable to the Company’s stockholders pursuant to the Merger Agreement, including any funds supplied by the Company or any Restricted Subsidiary for this purpose; (ii) the incurrence of indebtedness and/or guarantees of indebtedness incurred by Parent or any of the Parent Restricted Subsidiaries (as defined in Section 2.01 below) (including the Company and any of its Restricted Subsidiaries) necessary or used to fund the consideration payable to the Company’s stockholders in connection with the Alternative Merger, and the grant of any lien securing such indebtedness and guarantees; (iii) the guarantees of Parent’s outstanding indebtedness by the Restricted Subsidiaries immediately following the Post-Effective Merger; and (iv) the payment of fees and expenses in connection with any of the foregoing; provided that, immediately after giving effect to the consummation of all of the Alternative Merger, the Post-Effective Merger and the other transactions contemplated by the Merger Agreement or otherwise required to effect the Alternative Merger and the Post-Effective Merger, the Consolidated Coverage Ratio of Parent (as the successor to the Company under the Indenture after the Post-Effective Merger and the Assumption and Guarantee) would not be less than 2.00:1.00.

ARTICLE II

AMENDMENTS

Pursuant to Section 9.02 of the Indenture and subject to Section 3.01 below, the Indenture is hereby amended as follows:

Section 2.01  Amendments to Section 1.01 (Definitions).

Section 1.01 of the Indenture is hereby amended to add the following definitions in alphabetical order:

““Alternative Merger” means the merger of HoldCo with and into the Company, with the Company as the surviving corporation, on the terms and subject to the conditions set forth in the Merger Agreement.

“Assumption and Guarantee” means, upon the consummation of the Post-Effective Merger (if such merger occurs), Parent expressly assuming (and certain subsidiaries of Parent guaranteeing), by a separate supplement to this Indenture, the due and punctual payment of the principal of, and premium, if any, and interest on all of the Notes and the performance of every covenant of the Notes and this Indenture on the part of the Company to be performed and observed, all in accordance with the provisions of Section 4.17 and Article 5 of this Indenture.

“HoldCo” means PNK Holdings, Inc., a Delaware corporation and wholly-owned subsidiary of Parent.

“Merger Agreement” means that Agreement and Plan of Merger, dated as of December 20, 2012, among the Company, Parent, HoldCo and Merger Sub, as amended by the First Amendment to Agreement and Plan of Merger dated as of February 1, 2013, as further amended by the Second Amendment to Agreement and Plan of Merger dated as of March 14, 2013, and as further amended, modified, supplemented or restated.

“Merger Date” means the effective date of the consummation of the Post-Effective Merger.

“Merger Sub” means PNK Development 32, Inc., a Nevada corporation and wholly-owned subsidiary of HoldCo.

“Parent” means Pinnacle Entertainment, Inc., a Delaware corporation.

“Parent Restricted Subsidiary” means any subsidiary of Parent designated as a “Restricted Subsidiary” under any of the indentures governing Parent’s 8.625% Senior Notes due 2017, 8.75% Subordinated Notes due 2020 and 7.75% Subordinated Notes due 2022.

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“Planned Merger” means the merger of Merger Sub with and into the Company, with the Company as the surviving corporation, on the terms and subject to the conditions set forth in the Merger Agreement.

“Post-Effective Merger” means the merger of the Company with and into Parent, with Parent as the surviving corporation, which if the Alternative Merger occurs, will occur immediately or as promptly as practicable following the Alternative Merger.

“Transactions” means the Alternative Merger, the Post-Effective Merger and the other transactions contemplated by the Merger Agreement or otherwise required to effect the Alternative Merger and the Post-Effective Merger, including (i) the payment of the Merger consideration payable to the Company’s stockholders pursuant to the Merger Agreement, including any funds supplied by the Company or any Restricted Subsidiary for this purpose; (ii) the incurrence of indebtedness and/or guarantees of indebtedness incurred by Parent or any of the Parent Restricted Subsidiaries (including the Company and any of its Restricted Subsidiaries) necessary or used to fund the consideration payable to the Company’s stockholders in connection with the Alternative Merger, and the grant of any Lien securing such indebtedness and guarantees; (iii) the guarantees of Parent’s outstanding indebtedness by the Restricted Subsidiaries immediately following the Post-Effective Merger; and (iv) the payment of fees and expenses in connection with any of the foregoing.”

Section 2.02  Amendments to Section 4.07 (Restricted Payments).

Section 4.07(b) of the Indenture is hereby amended as follows:

(a)                                 Section 4.07(b) paragraph (14) is hereby amended by deleting the last word of such section (“or”).

(b)                                 Section 4.07(b) paragraph (15) is hereby amended by deleting the “.” at the end of such section and replacing it with “;”.

(c)                                  The following language shall be appended to Section 4.07(b) immediately following Section 4.07(b) paragraph (15):

“(16) any Restricted Payments made or deemed to be made in connection with the Alternative Merger, the Post-Effective Merger and the other Transactions, including any payments made and indebtedness and guarantees incurred by the Company, the Guarantors and any of the Restricted Subsidiaries; provided that, immediately after giving effect to the consummation of all of the Alternative Merger, the Post-Effective Merger and the other Transactions, the Company’s Consolidated Coverage Ratio would not be less than 2.00:1.00; or

(d)                                 The following language shall be appended to Section 4.07(b) immediately following the new paragraph (16) appended to Section 4.07(b) pursuant to Section 2.02(c) above:

“(17) effective only during the transitory period from the effective time of the Alternative Merger until the effective time of the Post-Effective Merger and the execution and delivery of the Assumption and Guarantee, any (i) payment by the Company and any of its Restricted Subsidiaries of dividends or any other distribution on their respective shares of Capital Stock, (ii) loans or advances by the Company and any of its Restricted Subsidiaries to or payment by the Company and any of its Restricted Subsidiaries of any Indebtedness or other obligations owed to Parent or to any Parent Restricted Subsidiary, and (iii) transfer by the Company or any of its Restricted Subsidiaries of any of their property or assets to Parent or any Parent Restricted Subsidiary.”

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(e)                                  The first sentence of the second paragraph of Section 4.07(b) is hereby deleted in its entirety and replaced with the following:

“In determining the aggregate amount of Restricted Payments made subsequent to the Issue Date, Restricted Payments made pursuant to clauses 3(a)(ii), 3(b)(ii), (5), (6), (7), (8), (9), (10), (11), (12), (13), (14), (16) or (17) of the immediately preceding paragraph shall, in each case, be excluded from such calculation; provided, that any amounts expended or liabilities incurred in respect of fees, premiums or similar payments in connection therewith shall be included in such calculation.”

Section 2.03  Amendments to Section 4.09 (Incurrence of Indebtedness and Issuance of Preferred Stock).

Section 4.09(b) clause (3) of the Indenture is hereby amended and restated in its entirety to read as follows:

“(3) Indebtedness Incurred by the Company or any Restricted Subsidiary pursuant to the Bank Credit Agreement or other Credit Facilities; provided that the aggregate principal amount of all such Indebtedness outstanding under this clause (3) as of any date of Incurrence (after giving pro forma effect to the application of the proceeds of such Incurrence), including all Permitted Refinancing Indebtedness Incurred to repay, redeem, extend, refinance, renew, replace, defease or refund any Indebtedness Incurred pursuant to this clause (3), shall not exceed the greater of

(i) $1.8 billion, and

(ii) 3.50x Consolidated EBITDA of the Company and its Restricted Subsidiaries for the twelve month period ended at the end of the most recent fiscal quarter for which financial statements are available (including pro forma adjustments to Consolidated EBITDA set forth in the definition of “Consolidated Coverage Ratio”),

to be reduced dollar-for-dollar by the aggregate amount of all Net Cash Proceeds of Asset Sales applied by an Obligor to repay Indebtedness under the Credit Facilities pursuant to Section 4.10 hereof; provided, however, that the aggregate amount of all Net Cash Proceeds of any Asset Sale completed to satisfy regulatory requirements in respect of the Planned Merger, the Alternative Merger or the Post-Effective Merger that are applied by an Obligor to repay Indebtedness under the Bank Credit Agreement or other Credit Facilities pursuant to Section 4.10 shall reduce dollar-for-dollar the amount set forth in the immediately preceding subclause (i) but not subclause (ii) of this clause (3) for purposes of determining the amount of Indebtedness permitted to be Incurred by the Company or any Restricted Subsidiary under this clause (3). Notwithstanding the foregoing, pro forma adjustments to Consolidated EBITDA set forth in the definition of “Consolidated Coverage Ratio” resulting from any such Asset Sales on or prior to any Determination Date shall be included in any calculation of Consolidated EBITDA pursuant to subclause (ii) of this clause (3).”

Section 2.04  Amendments to Section 11.04 (Merger, Consolidation or Sale of Assets of Guarantors).

Section 11.04(1) paragraph (b) of the Indenture is hereby amended and restated in its entirety to read as follows:

“(b) the Person (if other than the Guarantor) formed by such consolidation or into which the Guarantor is merged or the Person which acquires by sale, assignment, transfer, lease, conveyance or other disposition of the properties and assets of the Guarantor and its Subsidiaries, taken as a whole, (i) shall be a corporation, limited liability company, partnership or trust organized and validly existing under the laws of the United States or any State thereof or the District of Columbia and (ii) shall expressly assume, by supplemental indenture (in form satisfactory to the Trustee), executed and delivered to the Trustee, all the obligations of such Guarantor under its Guarantee, on the terms set forth in this Indenture;”.

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Section 2.05 Additional Amendments to Section 4.07 (Restricted Payments)

Section 4.07 of the Indenture is hereby further amended as follows:

(a)                                 Section 4.07(a) paragraph (3) of the Indenture is hereby deleted in its entirety and replaced with the following:

“(3) the aggregate amount of Restricted Payments (the amount expended for such purposes, if other than in cash, being the fair market value of such property as determined in the good faith reasonable judgment of the Company) exceeds or would exceed the sum, without duplication, of:

(A) 50% of the cumulative Consolidated Net Income (or if cumulative Consolidated Net Income shall be a loss, minus 100% of such loss) of the Company and the Restricted Subsidiaries during the period (treating such period as a single accounting period) beginning on the Merger Date and ending on the last day of the most recent fiscal quarter of the Company ending immediately prior to the date of the making of such Restricted Payment for which internal financial statements are available, plus

(B) 100% of the fair market value of the aggregate net proceeds received by the Company from any Person (other than from a Subsidiary of the Company) from the issuance and sale of Qualified Capital Stock of the Company or the amount by which Indebtedness of the Company or any Restricted Subsidiary is reduced by the conversion or exchange of debt securities or Disqualified Capital Stock into or for Qualified Capital Stock of the Company (to the extent that proceeds of the issuance of such Qualified Capital Stock would have been includable in this clause if such Qualified Capital Stock had been initially issued for cash) subsequent to the Merger Date and on or prior to the date of the making of such Restricted Payment (excluding any Qualified Capital Stock of the Company the purchase price of which has been financed directly or indirectly using funds (i) borrowed from the Company or any Restricted Subsidiary, unless and until and to the extent such borrowing is repaid, or (ii) contributed, extended, guaranteed or advanced by the Company or any Restricted Subsidiary (including, without limitation, in respect of any employee stock ownership or benefit plan)); provided that such aggregate net proceeds are limited to cash, Cash Equivalents and other Productive Assets, plus

(C) 100% of the aggregate cash received by the Company subsequent to the Merger Date and on or prior to the date of the making of such Restricted Payment upon the exercise of options or warrants (whether issued prior to or after the Merger Date) to purchase Qualified Capital Stock of the Company, plus

(D) to the extent that any Restricted Investment that was made after the Merger Date is sold for cash or Cash Equivalents or otherwise liquidated or repaid for cash or Cash Equivalents, or any dividends, distributions, interest payments, principal repayments or returns of capital are received by the Company or any Restricted Subsidiary in respect of any Restricted Investment, the proceeds of such sale, liquidation, repayment, dividend, distribution, principal repayment or return of capital, in each such case (i) reduced by the amount of any Amount Limitation Restoration (as defined below) for such Restricted Investment and (ii) valued at the cash or fair market value of Cash Equivalents received with respect to such Restricted Investment (less the cost of disposition, if any), and to the extent that any Restricted Investment consisting of a guarantee or other contingent obligation that was made after the Merger Date is terminated or cancelled, the excess, if any, of (x) the amount by which such Restricted Investment reduced the sum otherwise available for making Restricted Payments under this Section 4.07(a), over (y) the aggregate amount of payments made (including costs incurred) in respect of such guarantee or other contingent obligation, plus

(E) to the extent that any Person becomes a Restricted Subsidiary or an Unrestricted Subsidiary is redesignated as a Restricted Subsidiary after the Merger Date, the lesser of (i) the fair market value of the Restricted Investment of the Company and its Restricted Subsidiaries in such Person as of the date it becomes a Restricted Subsidiary or in such Unrestricted Subsidiary on the date of redesignation as a Restricted Subsidiary or (ii) the fair market value of such Restricted Investment as of the date such

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Restricted Investment was originally made in such Person or, in the case of the redesignation of an Unrestricted Subsidiary into a Restricted Subsidiary which Subsidiary was designated as an Unrestricted Subsidiary after the Merger Date, the amount of the Company and its Restricted Subsidiaries’ Restricted Investment therein as determined under Section 4.18 hereof, plus the aggregate fair market value of any additional Restricted Investments (each valued as of the date made) by the Company and its Restricted Subsidiaries in such Unrestricted Subsidiary after the Merger Date; provided that any amount so determined in (i) or (ii) shall be reduced to the extent that such Restricted Investment shall have been recouped as an Amount Limitation Restoration to the Amount Limitation of clause (5) below.

(b)                                 Section 4.07(b) paragraph (15) is hereby deleted in its entirety and replaced with the following:

“(15) other Restricted Payments not to exceed $75 million in the aggregate made on or after the Merger Date; provided no Default or Event of Default then exists or would result therefrom;”

(c)                                  The second and third paragraphs of Section 4.07(b) are hereby deleted in their entirety and replaced with the following:

“In determining the aggregate amount of Restricted Payments made subsequent to the Merger Date, Restricted Payments made pursuant to clauses 3(a)(ii), 3(b)(ii), (5), (6), (7), (8), (9), (10), (11), (12), (13), (14), (16) or (17) of the immediately preceding paragraph shall, in each case, be excluded from such calculation; provided, that any amounts expended or liabilities incurred in respect of fees, premiums or similar payments in connection therewith shall be included in such calculation. Restricted Payments under clause (15) shall be limited to the amount of $75 million set forth in such clause (an “Amount Limitation”). The Amount Limitation shall be permanently reduced at the time of any Restricted Payment made under such clause; provided, however, that to the extent that a Restricted Investment made under such clause is sold for cash or Cash Equivalents or otherwise liquidated or repaid for cash or Cash Equivalents, interest payments, principal repayments or returns of capital are received by the Company or any Restricted Subsidiary in respect of such Restricted Investment, valued, in each such case at the cash or marked-to-market value of Cash Equivalents received with respect to such Restricted Investment (less the cost of disposition, if any), or to the extent that any Restricted Investment consisting of a guarantee or other contingent obligation that was made after the Merger Date is terminated or cancelled, the excess, if any of (x) the amount by which such Restricted Investment counted toward the Amount Limitation, over (y) the aggregate amount of payments made (including costs incurred) in respect of such guarantee or other contingent obligation, then the Amount Limitation for such clause shall be increased by the amount so received by the Company or a Restricted Subsidiary or the amount of such excess of (x) over (y) (an “Amount Limitation Restoration”). In no event shall the aggregate Amount Limitation Restoration for a Restricted Investment exceed the original amount of such Restricted Investment.

With respect to clause (15) above, the Amount Limitation under such clause shall also be increased when any Person becomes a Restricted Subsidiary or an Unrestricted Subsidiary is redesignated as a Restricted Subsidiary (each such increase also referred to as an “Amount Limitation Restoration”) by the lesser of (i) the fair market value of the Restricted Investment made under clause (15) above in such Person as of the date it becomes a Restricted Subsidiary or in such Unrestricted Subsidiary as of the date of redesignation, as the case may be, or (ii) the fair market value of such Restricted Investment as of the date such Restricted Investment was originally made in such Person or, in the case of the redesignation of an Unrestricted Subsidiary into a Restricted Subsidiary which Subsidiary was designated as an Unrestricted Subsidiary after the Merger Date, the amount of the Company’s Restricted Investment therein as determined under Section 4.18 hereof, plus the aggregate fair market value of any additional Investments (each valued as of the date made) made under clause (15) above in such Unrestricted Subsidiary after the Merger Date.”

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ARTICLE III

MISCELLANEOUS

Section 3.01  Effectiveness of this Supplemental Indenture.

The Waivers and Amendments set forth in Articles I and II above shall become operative in respect of the Notes, and the terms of the Indenture and each Global Note shall be waived, amended, supplemented, modified or deleted as provided for in Articles I and II above:

(i)                                     as of the date of this Supplemental Indenture with respect to each of the Waivers set forth in Article I above;

(ii)                                  immediately prior to the effective time of the Planned Merger or the Alternative Merger with respect to each of the Amendments set forth in Sections 2.01, 2.03 and 2.04 above;

(iii)                               immediately prior to the effective time of the Alternative Merger, but not if the Planned Merger is consummated, with respect to the Amendments set forth in Section 2.02 above (other than Section 2.02(d) above);

(iv)                              solely during the transitory period from the effective time of the Alternative Merger until the effective time of the Post-Effective Merger and the execution and delivery of the Assumption and Guarantee with respect to the Amendments set forth in Section 2.02(d) above; and

(v)                                 immediately after the effective time of the Post-Effective Merger, but not before such effective time and not if the Planned Merger is consummated, with respect to the Amendments set forth in Section 2.05 above.

The Company shall give the Trustee prompt written notice of the occurrence of the effective time of the Planned Merger or the Alternative Merger and the Post-Effective Merger, or the termination of the Merger Agreement prior to consummation of either the Planned Merger or the Alternative Merger. If the Trustee receives written notice from the Company of the consummation of the Planned Merger, then none of the Amendments set forth in Section 2.02 or Section 2.05 shall become operative and they shall have no force and effect whatsoever without the need for further action hereunder.

Section 3.02  Governing Law.

THE INTERNAL LAW OF THE STATE OF NEW YORK WILL GOVERN AND BE USED TO CONSTRUE THIS SUPPLEMENTAL INDENTURE WITHOUT GIVING EFFECT TO APPLICABLE PRINCIPLES OF CONFLICTS OF LAW TO THE EXTENT THAT THE APPLICATION OF THE LAWS OF ANOTHER JURISDICTION WOULD BE REQUIRED THEREBY.

Section 3.03  Counterpart Originals.

The parties may sign any number of copies of this Supplemental Indenture.  Each signed copy shall be an original, but all of them together represent the same agreement.

Section 3.04  Ratification.

The Indenture, as supplemented by this Supplemental Indenture, shall remain in full force and effect and is in all respects ratified and confirmed.

Section 3.05  Severability.

In case any provision in this Supplemental Indenture is invalid, illegal or unenforceable, the validity, legality and enforceability of the remaining provisions will not in any way be affected or impaired thereby.

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Section 3.06  Headings, etc.

The Headings of the Articles and Sections of this Supplemental Indenture have been inserted for convenience of reference only, are not to be considered a part of this Supplemental Indenture and will in no way modify or restrict any of the terms or provisions hereof.

Section 3.07  The Trustee.

The Trustee shall not be responsible in any manner whatsoever for or in respect of the validity or sufficiency of this Supplemental Indenture or for or in respect of the recitals contained herein, all of which recitals are made solely by the Company and the Guarantors.

Section 3.08  Successor.

All agreements of the Company in this Supplemental Indenture will bind its successors. All agreements of the Trustee in this Indenture will bind its successors. All agreements of each Guarantor in this Indenture will bind its successors, except as otherwise provided in Section 11.06 of the Indenture.

(Signatures on following page)

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IN WITNESS WHEREOF, the parties hereto have caused this Supplemental Indenture to be duly executed and attested, all as of the date first above written.

[Signature page to Fourth Supplemental Indenture]