For the three months

Exhibit 4.2

FIRST SUPPLEMENTAL INDENTURE

first Supplemental Indenture (this “Supplemental Indenture”), dated as of July 16, 2009, among President Riverboat Casino-Missouri, Inc., a Missouri corporation (the “Guarantying Subsidiary”), a subsidiary of Pinnacle Entertainment, Inc. (or its permitted successor), a Delaware corporation (the “Company”), the Company, the other Guarantors (as defined in the Indenture referred to herein) and The Bank of New York Mellon Trust Company, N.A., as trustee under the Indenture referred to below (the “Trustee”).

W I T N E S S E T H

WHEREAS, the Company has heretofore executed and delivered to the Trustee an indenture (the “Indenture”), dated as of June 8, 2007 providing for the issuance of 7¹/2% Senior Subordinated Notes due 2012 (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 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.

3. No Recourse Against Others. No past, present or future director, officer, employee, incorporator, stockholder or agent of the Guarantying Subsidiary, as such, shall have any liability for any obligations of the Company or the Guarantying Subsidiary under the Notes, any Guaranties, 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. Such waiver may not be effective to waive liabilities under the federal securities laws and it is the view of the SEC that such a waiver is against public policy.

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.

[Signature pages follow]

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

		ACE GAMING, LLC,
		a New Jersey limited liability company
		By:		PNK Development 13, LLC,
				a New Jersey limited liability company,
		Its:		Sole Member
				By:		Biloxi Casino Corp.,
						a Mississippi corporation
				Its:		Sole Member
				By:		/s/ Stephen H. Capp
						Name:		Stephen H. Capp
						Title:		Chief Financial Officer and Treasurer
		AREH MLK LLC,
		a Delaware limited liability company
		By:		Biloxi Casino Corp.,
				a Mississippi corporation
		Its:		Sole Member
				By:		/s/ Stephen H. Capp
						Name:		Stephen H. Capp
						Title:		Chief Financial Officer and Treasurer
		MITRE ASSOCIATES LLC,
		a Delaware limited liability company
		By:		PNK Development 13, LLC,
				a New Jersey limited liability company,
		Its:		Sole Member
				By:		Biloxi Casino Corp.,
						a Mississippi corporation
				Its:		Sole Member
				By:		/s/ Stephen H. Capp
						Name:		Stephen H. Capp
						Title:		Chief Financial Officer and Treasurer

		PSW PROPERTIES LLC,
		a Delaware limited liability company
		By:		Biloxi Casino Corp.,
				a Mississippi corporation
		Its:		Sole Member
				By:		/s/ Stephen H. Capp
						Name:		Stephen H. Capp
						Title:		Chief Financial Officer and Treasurer
		PNK DEVELOPMENT 13, LLC,
		a New Jersey limited liability company
				By:		Biloxi Casino Corp.,
						a Mississippi corporation
				Its:		Sole Member
				By:		/s/ Stephen H. Capp
						Name:		Stephen H. Capp
						Title:		Chief Financial Officer and Treasurer

		PINNACLE ENTERTAINMENT, INC.,
		a Delaware corporation
		BILOXI CASINO CORP.,
		a Mississippi corporation
		CASINO MAGIC CORP.,
		a Minnesota corporation
		CASINO ONE CORPORATION,
		a Mississippi corporation
		PNK (BOSSIER CITY), INC.,
		a Louisiana corporation
		ST. LOUIS CASINO CORP.,
		a Missouri corporation
		By:		/s/ Stephen H. Capp
				Name:		Stephen H. Capp
				Title:		Chief Financial Officer and/or Treasurer

		BELTERRA RESORT INDIANA, LLC,
		a Nevada limited liability company
		By:		Pinnacle Entertainment, Inc,
		Its:		Sole Member
				By:		/s/ Stephen H. Capp
						Name:		Stephen H. Capp
						Title:		Chief Financial Officer
		BOOMTOWN, LLC,
		a Delaware limited liability company
		By:		Pinnacle Entertainment, Inc,
		Its:		Sole Member
				By:		/s/ Stephen H. Capp
						Name:		Stephen H. Capp
						Title:		Chief Financial Officer
		PNK (LAKE CHARLES), L.L.C.,
		a Louisiana limited liability company
		By:		Pinnacle Entertainment, Inc.,
		Its:		Sole Member
				By:		/s/ Stephen H. Capp
						Name:		Stephen H. Capp
						Title:		Chief Financial Officer
		PNK (RENO), LLC,
		a Nevada limited liability company
		By:		Pinnacle Entertainment, Inc,
		Its:		Sole Member
				By:		/s/ Stephen H. Capp
						Name:		Stephen H. Capp
						Title:		Chief Financial Officer

		LOUISIANA-I GAMING,
		a Louisiana Partnership in Commendam
		By:		Boomtown, LLC,
		Its:		General Partner
				By:		Pinnacle Entertainment, Inc.,
						its Sole Member
						By:		/s/ Stephen H. Capp
								Name: Stephen H. Capp
								Title:   Chief Financial Officer

		By:		Pinnacle Entertainment, Inc.,
		Its:		Partner
				By:		/s/ Stephen H. Capp
						Name:		Stephen H. Capp
						Title:		Chief Financial Officer
		PNK (ES), LLC,
		a Delaware limited liability company
		By:		Pinnacle Entertainment, Inc.
		Its:		Sole Member
				By:		/s/ Stephen H. Capp
						Name:		Stephen H. Capp
						Title:		Chief Financial Officer
		PNK (ST. LOUIS RE), LLC,
		a Delaware limited liability company
		By:		Pinnacle Entertainment, Inc.
		Its:		Sole Member
				By:		/s/ Stephen H. Capp
						Name:		Stephen H. Capp
						Title:		Chief Financial Officer

		AREP BOARDWALK PROPERTIES LLC,
		a Delaware limited liability company
		By:		Biloxi Casino Corp.
		its:		Sole Member
				By:		/s/ Stephen H. Capp
						Name:		Stephen H. Capp
						Title:		Chief Financial Officer and Treasurer
		PNK DEVELOPMENT 7, LLC,
		a Delaware limited liability company
		By:		Pinnacle Entertainment, Inc.
		Its:		Sole Member
				By:		/s/ Stephen H. Capp
						Name:		Stephen H. Capp
						Title:		Chief Financial Officer
		PNK DEVELOPMENT 8, LLC,
		a Delaware limited liability company
		By:		Pinnacle Entertainment, Inc.
		Its:		Sole Member
				By:		/s/ Stephen H. Capp
						Name:		Stephen H. Capp
						Title:		Chief Financial Officer
		PNK DEVELOPMENT 9, LLC,
		a Delaware limited liability company
		By:		Pinnacle Entertainment, Inc.
		Its:		Sole Member
				By:		/s/ Stephen H. Capp
						Name:		Stephen H. Capp
						Title:		Chief Financial Officer

		PNK (SCB), L.L.C.,
		a Louisiana limited liability company
		By:		PNK Development 7, LLC,
		Its:		Sole Member
				By:		Pinnacle Entertainment, Inc.
				Its:		Sole Member
						By:		/s/ Stephen H. Capp
								Name:		Stephen H. Capp
								Title:		Chief Financial Officer
		PNK (BATON ROUGE) PARTNERSHIP,
		a Louisiana partnership
		By:		PNK Development 8, LLC,
		Its:		Partner
				By:		Pinnacle Entertainment, Inc.,
				Its:		Sole Member
						By:		/s/ Stephen H. Capp
								Name:		Stephen H. Capp
								Title:		Chief Financial Officer
		By:		PNK Development 9, LLC,
		Its:		Partner
				By:		Pinnacle Entertainment, Inc.,
				Its:		Sole Member
						By:		/s/ Stephen H. Capp
								Name:		Stephen H. Capp
								Title:		Chief Financial Officer

		PNK (CHILE 1), LLC,
		a Delaware limited liability company
		By:		Pinnacle Entertainment, Inc.,
				a Delaware corporation,
		Its:		Sole Member
				By:		/s/ Stephen H. Capp
						Name:		Stephen H. Capp
						Title:		Chief Financial Officer
		PNK (CHILE 2), LLC,
		a Delaware limited liability company
		By:		Pinnacle Entertainment, Inc.,
				a Delaware corporation,
		Its:		Sole Member
				By:		/s/ Stephen H. Capp
						Name:		Stephen H. Capp
						Title:		Chief Financial Officer
		PNK (STLH), LLC,
		a Delaware limited liability company
		By:		Pinnacle Entertainment, Inc.,
				a Delaware corporation
		Its:		Sole Member
				By:		/s/ Stephen H. Capp
						Name:		Stephen H. Capp
						Title:		Chief Financial Officer
		PRESIDENT RIVERBOAT CASINO-MISSOURI, INC., a
		Missouri corporation
		By:		/s/ Stephen H. Capp
				Name:		Stephen H. Capp
				Title:		Chief Financial Officer and Treasurer

		YANKTON INVESTMENTS, LLC,
		a Nevada limited liability company
		By:		/s/ John A. Godfrey
				Name:		John A. Godfrey
				Its:		Sole Manager

		OGLE HAUS, LLC,
		an Indiana limited liability company
		By:		Belterra Resorts Indiana, LLC,
				a Nevada limited liability company
		Its:		Sole Member
				By:		Pinnacle Entertainment, Inc.,
						a Delaware corporation,
				Its:		Sole Member
						By:		/s/ Stephen H. Capp
								Name: Stephen H. Capp
								Title:   Chief Financial Officer