Rocky Mountain Pipeline System LLC Announces Extension of Open Season for Proposed Crude Oil Transportation Route from Fort Laramie, Wyoming to Cushing, Oklahoma

Rocky Mountain Pipeline System LLC (“RMPS”), an indirect subsidiary of Plains All American Pipeline, L.P. (NYSE:PAA), announced today that it has extended the response deadline and modified the required volume commitments and associated tariff rates of its previously announced open season for committed capacity on a proposed crude oil transportation route from Fort Laramie, Wyoming to Cushing, Oklahoma. The open season process provides an opportunity for potential shippers to offer long-term volume commitments for service between Fort Laramie, Wyoming and Cushing, Oklahoma in exchange for a discounted rate.

By submitting a binding proposal, bidders are offering to enter into a long-term throughput and deficiency agreement for pipeline capacity. Interested parties should contact Gregg Werger, Manager – Pipeline Commercial Operations at (303) 572-4906 or gawerger@paalp.com. A complete package of open season documents is available online under the RMPS Ft. Laramie to Cushing Open Season tab of the Customer Center section of PAA’s website at www.paalp.com. The open season extension begins on June 23, 2008 and will end at 5:00 P.M. MST on July 7, 2008.

Plains All American Pipeline, L.P. is a publicly traded master limited partnership engaged in the transportation, storage, terminalling and marketing of crude oil, refined products and liquefied petroleum gas and other natural gas related petroleum products. Through its 50% ownership in PAA/Vulcan Gas Storage, LLC, the Partnership is also engaged in the development and operation of natural gas storage facilities. The Partnership is headquartered in Houston, Texas.