SEC Form 4 
FORM 4	UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

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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	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).			
1. Name and Address of Reporting Person*
Plains All American GP LLC	

(Last)	(First)	(Middle)	
333 CLAY STREET, SUITE 1600	

(Street) 
HOUSTON	TX	77002	

(City)	(State)	(Zip)	
	2. Issuer Name and Ticker or Trading Symbol 
PAA NATURAL GAS STORAGE LP [ PNG ] 	5. Relationship of Reporting Person(s) to Issuer 
(Check all applicable) 
	Director	X	10% Owner	
	Officer (give title below)		Other (specify below)	

	3. Date of Earliest Transaction (Month/Day/Year)
09/09/2010 		
	4. 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 Acquired, Disposed of, or Beneficially Owned	
1. Title of Security (Instr. 3) 	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8) 	4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5) 	5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 	7. Nature of Indirect Beneficial Ownership (Instr. 4) 	
			Code	V	Amount	(A) or (D)	Price				
Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities) 	
1. Title of Derivative Security (Instr. 3) 	2. Conversion or Exercise Price of Derivative Security 	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8) 	5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 	6. Date Exercisable and Expiration Date (Month/Day/Year)	7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4) 	8. Price of Derivative Security (Instr. 5) 	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 	11. Nature of Indirect Beneficial Ownership (Instr. 4) 	
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares					
Phantom Common Units(2) 	$0 	09/09/2010		J			125,000	(2) 	05/05/2012	Common Units	125,000	$0 	0	I	See Footnote(1) 	
Phantom Series A Subordinated Units(2) 	$0 	09/09/2010		J			125,000	(2) 	(3) 	Common Units	125,000	$0 	0	I	See Footnote(1) 	
Phantom Series B Subordinated Units(2) 	$0 	09/09/2010		J			125,000	(2) 	(3) 	Common Units or Series A Subordinated Units(2) 	125,000	$0 	0	I	See Footnote(1) 	
1. Name and Address of Reporting Person*
Plains All American GP LLC	

(Last)	(First)	(Middle)	
333 CLAY STREET, SUITE 1600	

(Street) 
HOUSTON	TX	77002	

(City)	(State)	(Zip)	
	
1. Name and Address of Reporting Person*
Plains AAP, L.P.	

(Last)	(First)	(Middle)	
333 CLAY STREET, SUITE 1600	

(Street) 
HOUSTON	TX	77002	

(City)	(State)	(Zip)	
	
1. Name and Address of Reporting Person*
PAA GP LLC	

(Last)	(First)	(Middle)	
333 CLAY STREET, SUITE 1600	

(Street) 
HOUSTON	TX	77002	

(City)	(State)	(Zip)	
	
1. Name and Address of Reporting Person*
PLAINS ALL AMERICAN PIPELINE LP	

(Last)	(First)	(Middle)	
333 CLAY STREET, SUITE 1600	

(Street) 
HOUSTON	TX	77002	

(City)	(State)	(Zip)	
	
Explanation of Responses:	
1. The reporting person, PAA GP LLC, is the general partner of Plains All American Pipeline, L.P. ("PAA"), the record holder of the units. Plains AAP, L.P. owns all of the membership interests in PAA GP LLC and Plains All American GP LLC is the general partner of Plains AAP, L.P. Accordingly, Plains All American GP LLC, Plains AAP, L.P. and PAA GP LLC may be deemed to be indirect beneficial owners of any securities held by PAA.	
2. On September 9, 2010, PAA issued the phantom units reported above by entering into agreements with Greg L. Armstrong, Harry N. Pefanis and Al Swanson pursuant to which these individuals acquired from PAA for no consideration the right to receive Common Units and Series A Subordinated Units convertible into Common Units of PAA Natural Gas Storage, L.P. ("PNG") that are currently held by PAA. These individuals also acquired distribution equivalent rights (payable by PAA in cash) with respect to the phantom common units and phantom series A subordinated units. Pursuant to the terms of the agreements, the phantom units reported above will vest and be payable as follows: (i) the phantom common units will vest 50% on May 5, 2011 and 50% on May 5, 2012, and be payable one-for-one by PAA in Common Units of PNG; (ii) the phantom series A subordinated units will vest in connection with the conversion of the Series A Subordinated Units into Common Units, and be payable one-for-one by PAA in Common Units of PNG; and (iii) the phantom series B subordinated units will vest in tranches of 20%, 21%, 15%, 22% and 22%, respectively, in connection with the conversion of the First through Fifth Tranches of Series B Subordinated Units. Upon vesting, the phantom series B subordinated units will be payable one-for-one by PAA in Series A Subordinated Units or Common Units of PNG it receives upon conversion of the Series B Subordinated Units. Terms used but not defined herein shall have the meanings set forth in the Second Amended and Restated Agreement of Limited Partnership of PNG.	
3. Any phantom series A subordinated units and any phantom series B subordinated units that have not vested as of December 18, 2018 will be automatically cancelled on such date. Note: On August 16, 2010, the general partner of PNG executed an amendment to PNG's Amended and Restated Agreement of Limited Partnership pursuant to which the number of Series A Subordinated Units held by PAA was reduced by 2 million units (from 13,934,351 units to 11,934,351 units) and the number of Series B Subordinated Units held by PAA was increased by an equivalent amount (from 11,500,000 units to 13,500,000 units). The Series A Subordinated Units and Series B Subordinated Units will convert into Common Units or Series A Subordinated Units, as applicable, on a one-for-one basis in accordance with their terms as set forth in PNG's Second Amended and Restated Agreement of Limited Partnership.	
Remarks:	
	
	By: /s/ Tim Moore, Vice President	09/10/2010	
	** Signature of Reporting Person	Date	
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.	
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).	
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).	
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.	
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