SUPPLEMENTAL INDENTURE

SUPPLEMENTAL INDENTURE (this “Supplemental Indenture”), dated as of February 23, 2012, among Ameristar Casino Springfield, LLC, a Massachusetts limited liability company (the “Guarantying Subsidiary”), a subsidiary of Ameristar Casinos, Inc., a Nevada corporation (the “Company”), the Company, the other Guarantors (as defined in the Indenture referred to herein) and Wilmington Trust, National Association (as successor by merger to Wilmington Trust FSB) as trustee under the Indenture referred to below (the “Trustee”).

WHEREAS, the Company has heretofore executed and delivered to the Trustee an indenture (the “Indenture”), dated as of April 14, 2011 providing for the issuance of 7.50% Senior Notes due 2021 (the “Notes”);

WHEREAS, the Indenture provides that under certain circumstances the Guarantying Subsidiary shall execute and deliver to the Trustee a supplemental indenture pursuant to which the Guarantying Subsidiary shall unconditionally guarantee all of the Company's Obligations under the Notes and the Indenture on the terms and conditions set forth herein (the “Guaranty”); and

WHEREAS, pursuant to Section 9.01 of the Indenture, the Trustee is authorized to execute and deliver this Supplemental Indenture.

NOW, THEREFORE, in consideration of the foregoing and for other good and valuable consideration, the receipt of which is hereby acknowledged, the Guarantying Subsidiary and the Trustee mutually covenant and agree for the equal and ratable benefit of the Holders of the Notes as follows:

1.    CAPITALIZED TERMS. Capitalized terms used herein without definition shall have the meanings assigned to them in the Indenture.

2.    AGREEMENT TO GUARANTY. The Guarantying Subsidiary hereby agrees to provide, and does hereby provide, an unconditional Guaranty on the terms and subject to the conditions set forth in the Guaranty and in the Indenture including but not limited to Article 11 thereof (which is hereby incorporated by reference).

3.    NO RECOURSE AGAINST OTHERS. No past, present or future director, officer, employee, agent, manager, partner, member, incorporator or stockholder of the Guarantying Subsidiary (or of any stockholder of the Company), as such, shall have any liability for any obligations of the Company or any Guarantying Subsidiary under the Notes, any Guarantees, the Indenture or this Supplemental Indenture or for any claim based on, in respect of, or by reason of, such obligations or their creation. Each Holder of the Notes by accepting a Note waives and releases all such liability. The waiver and release are part of the consideration for issuance of the Notes.

4.    NEW YORK LAW TO GOVERN. THE INTERNAL LAW OF THE STATE OF NEW YORK SHALL 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.

5.    COUNTERPARTS. 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.

6.    EFFECT OF HEADINGS. The Section headings herein are for convenience only and shall not affect the construction hereof.

7.    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 Guarantying Subsidiary and the Company.

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.

Dated: February 23, 2012

AMERISTAR CASINO SPRINGFIELD, LLC

By:    /s/ Peter C. Walsh                

Name: Peter C. Walsh    

Title: Vice President

AMERISTAR CASINOS, INC.

By:    /s/ Peter C. Walsh                

Name: Peter C. Walsh

Title: Senior Vice President and General Counsel

CACTUS PETE'S, INC.

AMERISTAR CASINO VICKSBURG, INC.

AMERISTAR CASINO COUNCIL BLUFFS, INC.

AMERISTAR CASINO LAS VEGAS, INC.

A.C. FOOD SERVICES, INC.

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

By:    /s/ Peter C. Walsh                

Name: Peter C. Walsh

Title: Vice President

WILMINGTON TRUST, NATIONAL ASSOCIATION, as Trustee

By:    /s/ Jane Schweiger                

Name: Jane Schweiger

Title: Vice President