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Exhibit 4.10    
    




MARKWEST ENERGY PARTNERS, L.P.
 MARKWEST ENERGY FINANCE CORPORATION

and

the Subsidiary Guarantors named herein 




6.875% SENIOR NOTES DUE 2014 




SECOND SUPPLEMENTAL INDENTURE
 DATED AS OF JANUARY 17, 2006 




WELLS FARGO BANK, NATIONAL ASSOCIATION,
 Trustee 














        This SUPPLEMENTAL INDENTURE, dated as of January 17, 2006 is among MarkWest Energy Partners, L.P., a Delaware limited partnership (the "Partnership"), MarkWest Energy Finance
Corporation, a Delaware corporation ("MarkWest Finance" and, together with the Partnership, the "Issuers"), each of the parties identified under the caption "Subsidiary Guarantors" on the signature
page hereto (the "Subsidiary Guarantors") and Wells Fargo Bank, National Association, a national banking association, as Trustee. 


RECITALS 


        WHEREAS,
the Issuers, the initial Subsidiary Guarantors and the Trustee entered into an Indenture, dated as of October 25, 2004 (as amended and supplemented, the "Indenture"),
pursuant to which the Issuers have issued $225,000,000 in principal amount of 6.875% Senior Notes due 2014 (the "Notes"); 


        WHEREAS,
Section 9.01(d) of the Indenture provides that the Issuers, the Subsidiary Guarantors and the Trustee may amend or supplement the Indenture in order to add Subsidiary
Guarantors pursuant to Section 4.13 or 5.01(c) thereof, without the consent of the Holders of the Notes; and 



        WHEREAS,
all acts and things prescribed by the Indenture, by law and by the Certificate of Incorporation and the Bylaws (or comparable constituent documents) of the Issuers, of the
Subsidiary Guarantors and of the Trustee necessary to make this Supplemental Indenture a valid instrument legally binding on the Issuers, the Subsidiary Guarantors and the Trustee, in accordance with
its terms, have been duly done and performed; 


        NOW,
THEREFORE, to comply with the provisions of the Indenture and in consideration of the above premises, the Issuers, the Subsidiary Guarantors and the Trustee covenant and agree for
the equal and proportionate benefit of the respective Holders of the Notes as follows: 


ARTICLE 1 


        Section 1.01.    This Supplemental Indenture is supplemental to the Indenture and does and shall be deemed to
form a part of, and shall be construed in connection with and as part of, the Indenture for any and all purposes. 


        Section 1.02.    This Supplemental Indenture shall become effective immediately upon its execution and delivery by each
of the Issuers, the Subsidiary Guarantors and the Trustee. 


ARTICLE 2 


        From
this date, in accordance with Section 4.13 or 5.01(c) and by executing this Supplemental Indenture, the Guarantors whose signatures appear below are subject to the provisions
of the Indenture to the extent provided for in Article 10 thereunder. 


ARTICLE 3 


        Section 3.01.    Except as specifically modified herein, the Indenture and the Notes are in all respects ratified and
confirmed (mutatis mutandis) and shall remain in full force and effect in accordance with their terms with all capitalized terms used herein without
definition having the same respective meanings ascribed to them as in the Indenture. 


        Section 3.02.    Except as otherwise expressly provided herein, no duties, responsibilities or liabilities are assumed,
or shall be construed to be assumed, by the Trustee by reason of this Supplemental Indenture. This Supplemental Indenture is executed and accepted by the Trustee subject to all the terms and
conditions set forth in the Indenture with the same force and effect as if those terms and conditions were repeated at length herein and made applicable to the Trustee with respect hereto. 







 



        Section 3.03.    THIS SUPPLEMENTAL INDENTURE SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE
STATE OF NEW YORK. 



        Section 3.04.    The parties may sign any number of copies of this Supplemental Indenture. Each signed copy shall be an
original, but all of such executed copies together shall represent the same agreement. 


[NEXT
PAGE IS SIGNATURE PAGE] 


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



	 	 	Issuers:
	

 	
 	

MARKWEST ENERGY PARTNERS, L.P.
	

 	
 	

By:	

MARKWEST ENERGY GP, L.L.C., its general partner
	

 	
 	

 	

By:	

/s/  ANDREW L. SCHROEDER      

	 	 	 	 	Name:	Andrew L. Schroeder
	 	 	 	 	Title:	Vice President
	

 	
 	
MARKWEST ENERGY FINANCE CORPORATION
	

 	
 	

By:	

 	

/s/  ANDREW L. SCHROEDER      

	 	 	 	 	Name:	Andrew L. Schroeder
	 	 	 	 	Title:	Vice President




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	 	 	Subsidiary Guarantors:
	

 	
 	

MARKWEST ENERGY OPERATING COMPANY, L.L.C.

BASIN PIPELINE L.L.C.

WEST SHORE PROCESSING COMPANY, L.L.C.

MARKWEST ENERGY APPALACHIA, L.L.C.

MARKWEST TEXAS GP, L.L.C.

MW TEXAS LIMITED, L.L.C.

MARKWEST MICHIGAN PIPELINE COMPANY, L.L.C.

MARKWEST WESTERN OKLAHOMA GAS COMPANY, L.L.C.
	

 	
 	

By:	

/s/  ANDREW L. SCHROEDER      

	 	 	 	Name:	Andrew L. Schroeder
	 	 	 	Title:	Vice President





	 	 	MARKWEST POWER TEX L.P.

MARKWEST PINNACLE L.P.

MARKWEST PNG UTILITY L.P.

MARKWEST TEXAS PNG UTILITY L.P.

MARKWEST BLACKHAWK L.P.

MARKWEST NEW MEXICO L.P.

MARKWEST ENERGY EAST TEXAS GAS COMPANY L.P.

MARKWEST PIPELINE COMPANY, L.P.

MARKWEST JAVELINA PIPLELINE HOLDING, L.P.

MARKWEST JAVELINA HOLDING COMPANY, L.P.
	

 	
 	

By:	

MARKWEST TEXAS GP, L.L.C., its general partner
	

 	
 	

 	

By:	

/s/  ANDREW L. SCHROEDER      

	 	 	 	 	Name:	Andrew L. Schroeder
	 	 	 	 	Title:	Vice President




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	 	 	MARKWEST JAVELINA COMPANY

MARKWEST JAVELINA PIPELINE COMPANY
	

 	
 	

By:	

MARKWEST JAVELINA HOLDING COMPANY, L.P. a partner
	

 	
 	

By:	

MARKWEST TEXAS GP, L.L.C., its general partner
	

 	
 	

 	

By:	

/s/  ANDREW L. SCHROEDER      

	 	 	 	 	Name:	Andrew L. Schroeder
	 	 	 	 	Title:	Vice President
	

 	
 	

By:	

MARKWEST JAVELINA PIPELINE HOLDING, L.P. a partner
	

 	
 	

By:	

MARKWEST TEXAS GP, L.L.C., its general partner
	

 	
 	

 	

By:	

/s/  ANDREW L. SCHROEDER      

	 	 	 	 	Name:	Andrew L. Schroeder
	 	 	 	 	Title:	Vice President





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	 	 	Trustee:
	

 	
 	

WELLS FARGO BANK, NATIONAL ASSOCIATION, as Trustee
	

 	
 	

By:	

/s/  MELISSA A. SCOTT      

	 	 	 	Name:	Melissa A. Scott
	 	 	 	Title:	Vice President




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Exhibit 4.10