SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person* First Reserve GP XI, Inc. (Last) (First) (Middle) C/O FRC FOUNDERS CORPORATION ONE LAFAYETTE PLACE (Street) GREENWICH CT 06830 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 10/01/2010	3. Issuer Name and Ticker or Trading Symbol Crestwood Midstream Partners LP [ CMLP ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)	5. If Amendment, Date of Original Filed (Month/Day/Year)
			6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common units representing limited partner interests	5,696,752	I	See Footnote.(1)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Subordinated units representing limited partner interests	(2)	(2)	Common units representing limited partner interests	11,513,625	(2)	I	See Footnote.(1)

1. Name and Address of Reporting Person* First Reserve GP XI, Inc. (Last) (First) (Middle) C/O FRC FOUNDERS CORPORATION ONE LAFAYETTE PLACE (Street) GREENWICH CT 06830 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* MACAULAY WILLIAM E (Last) (First) (Middle) C/O FRC FOUNDERS CORPORATION ONE LAFAYETTE PLACE (Street) GREENWICH CT 06830 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* First Reserve GP XI, L.P. (Last) (First) (Middle) C/O FRC FOUNDERS CORPORATION ONE LAFAYETTE PLACE (Street) GREENWICH CT 06830 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* FR Midstream Holdings LLC (Last) (First) (Middle) C/O FRC FOUNDERS CORPORATION ONE LAFAYETTE PLACE (Street) GREENWICH CT 06830 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* FR XI CMP Holdings LLC (Last) (First) (Middle) C/O FRC FOUNDERS CORPORATION ONE LAFAYETTE PLACE (Street) GREENWICH CT 06830 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Crestwood Holdings Partners, LLC (Last) (First) (Middle) 717 TEXAS AVENUE, SUITE 3150 (Street) HOUSTON TX 77002 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Crestwood Holdings II LLC (Last) (First) (Middle) 717 TEXAS AVENUE, SUITE 3150 (Street) HOUSTON TX 77002 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Crestwood Holdings LLC (Last) (First) (Middle) 717 TEXAS AVENUE, SUITE 3150 (Street) HOUSTON TX 77002 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Crestwood Gas Services Holdings LLC (Last) (First) (Middle) 717 TEXAS AVENUE, SUITE 3150 (Street) HOUSTON TX 77002 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. These units are owned directly by Crestwood Gas Services Holdings LLC, whose sole member is Crestwood Holdings LLC, whose sole member is Crestwood Holdings II LLC, whose sole member is Crestwood Holdings Partners, LLC, whose controlling member is FR XI CMP Holdings LLC, whose sole member is FR Midstream Holdings LLC, whose managing member is First Reserve GP XI, L.P., whose general partner is First Reserve GP XI, Inc. William E. Macaulay is a director of First Reserve GP XI, Inc. and has the right to appoint a majority of the board of directors of First Reserve GP XI, Inc.

2. Each subordinated unit will convert into one common unit upon the termination of the subordination period under certain circumstances as set forth in the Second Amended and Restated Agreement of Limited Partnership of Crestwood Midstream Partners LP. The subordinated units have no expiration date.

	/s/ Michael France, Vice President for First Reserve GP XI, Inc.	10/11/2010
	/s/ William Macaulay	10/11/2010
	/s/ Michael France, Vice President for First Reserve GP XI, Inc., the General Partner of First Reserve GP XI, L.P.	10/11/2010
	/s/ Michael France, Vice President for First Reserve GP XI, Inc., the General Partner of First Reserve GP XI, L.P., the Managing Member of FR Midstream Holdings LLC	10/11/2010
	/s/ Michael France, Vice President for First Reserve GP XI, Inc., the General Partner of First Reserve GP XI, L.P., the Managing Member of FR Midstream Holdings LLC, the Managing Member of FR XI CMP Holdings LLC	10/11/2010
	/s/ Robert G. Phillips, President for Crestwood Holdings Partners, LLC	10/11/2010
	/s/ Robert G. Phillips, President for Crestwood Holdings II LLC	10/11/2010
	/s/ Robert G. Phillips, President for Crestwood Holdings LLC	10/11/2010
	/s/ Robert G. Phillips, President for Crestwood Holdings LLC, the Member of Crestwood Gas Services Holdings LLC	10/11/2010
	** Signature of Reporting Person	Date
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