X0303 4 2009-08-27 0001070423 PLAINS ALL AMERICAN PIPELINE LP PAA 0000904057 ALLEN PAUL G 505 FIFTH AVENUE S, SUITE 900 SEATTLE 98104 0 0 1 0 Common Units 2009-08-27 4 J 0 1907305 47.19 A 1907305 I See Footnotes Common Units 12390120 I Through Corporation Common Units 1995954 I See Footnotes On August 27, 2009, Vulcan Gas Storage, LLC ("VGS") became entitled to purchase 1,907,305 common units of the Issuer pursuant to the terms of the Membership Interest Purchase Agreement, dated as of August 27, 2009, between VGS, the Issuer and a subsidiary of the Issuer. The Reporting Person owns 16,293,379 Common Units of the Issuer, of which: (i) 1,907,305 are owned directly by VGS, a limited liability company that is indirectly controlled by the Reporting person; (ii) 12,390,120 are owned directly by a corporation that is controlled by the Reporting Person; and (iii) 1,995,954 are owned directly by another limited liability company that is indirectly controlled by the Reporting Person. The Reporting Person disclaims beneficial ownership of the reported securities, except to the extent of his pecuniary interest therein. /s/ W. Lance Conn, Attorney-in-fact for Paul G. Allen 2009-08-28