Rio Vista Energy Partners L.P. (Rio Vista), a Delaware limited partnership, was formed by Penn Octane Corporation (Penn Octane) on July 10, 2003 and was a wholly owned subsidiary of Penn Octane until September 30, 2004, the date that Penn Octane completed a series of transactions that (i) transferred  substantially all of its owned pipeline and terminal assets in Brownsville, Texas and Matamoros, Mexico and certain immaterial liabilities to Rio Vista Operating Partnership L.P. (RVOP) (ii) transferred Penn Octane’s 99.9% interest in RVEP to Rio Vista and (iii) distributed all of its limited partnership interests (Common Units) in Rio Vista to its common stockholders (Spin-Off), resulting in Rio Vista becoming a separate public company.  The Common Units represented 98% of Rio Vista’s outstanding capital and 100% of Rio Vista’s limited partnership interests.  The remaining 2% represented the general partner interest.  The general partner interest is solely owned and controlled by Rio Vista GP LLC (General Partner).  Prior to June 30, 2006, the General Partner was wholly owned by Penn Octane. On July 1, 2006, options to acquire 50% of the General Partner were exercised, resulting in Penn Octane having a 50% interest in the General Partner.  Penn Octane retains control over the General Partner pursuant to a voting agreement with the other owners of the General Partner.  The General Partner is responsible for the management of Rio Vista.  Common unitholders do not participate in the management of Rio Vista.   Rio Vista Energy Partners L.P. and its consolidated subsidiaries (not including the General Partner) are hereinafter referred to as “Rio Vista”.

Prior to the sale of a portion of Rio Vista’s LPG related assets and all of Penn Octane’s liquefied petroleum gas (LPG) related assets to TransMontaigne Product Services Inc. (TransMontaigne) on August 22, 2006 (Restated LPG Asset Sale) discussed below, Rio Vista was principally engaged in the purchase, transportation and sale of LPG.    Subsequent to the Restated LPG Asset Sale, Rio Vista continues to own and operate a LPG terminal facility in Matamoros, Tamaulipas, Mexico (Matamoros Terminal Facility) and approximately 23 miles of pipelines (US - Mexico Pipelines) which connects the Matamoros Terminal Facility to the LPG terminal facility in Brownsville, Texas sold to TransMontaigne. Pursuant to a LPG transportation agreement with TransMontaigne, Rio Vista uses its remaining LPG assets to transport LPG exclusively for TransMontaigne on a fee-for-services basis.

Subsequent to the Spin-Off, and through the date of the Restated LPG Asset Sale, Rio Vista sold LPG directly to P.M.I. Trading Limited (PMI).  PMI is a subsidiary of Petróleos Mexicanos, the state-owned Mexican oil company, which is commonly known by its trade name “PEMEX.”  PMI is currently the exclusive importer of LPG into Mexico.  Rio Vista purchased LPG from Penn Octane under a long-term supply agreement.  The purchase price to Rio Vista of the LPG sold from Penn Octane was determined based on the cost of LPG under Penn Octane’s LPG supply agreements with its suppliers, other direct costs related to PMI sales and a formula that took into consideration operating costs of Penn Octane and Rio Vista.   Prior to the Restated LPG Asset Sale, Rio Vista’s primary customer for LPG was PMI.  PMI sells the LPG delivered from the Matamoros Terminal Facility to PEMEX which distributes the LPG into the northeastern region of Mexico.  Subsequent to the Restated LPG Asset Sale, TransMontaigne continues to use the Matamoros Terminal Facility for sales of LPG to PMI which are principally destined for consumption in the northeastern region of Mexico, which includes the states of Coahuila, Nuevo Leon and Tamaulipas.  Sales of LPG to PMI have historically fluctuated in part based on the seasons.  The demand for LPG is strongest during the winter season. 

All of Rio Vista’s LPG operations are conducted through, and Rio Vista’s LPG operating assets are owned by, RVOP.  The General Partner is entitled to receive distributions on its general partner interest and additional incentive distributions as provided for in Rio Vista’s partnership agreement.  The General Partner has sole responsibility for conducting Rio Vista’s business and for managing Rio Vista’s operations in accordance with the partnership agreement. The General Partner does not receive any management fee or other compensation in connection with its management of Rio Vista’s business, but is entitled to be reimbursed for all direct and indirect expenses incurred on Rio Vista’s behalf.

Rio Vista does not anticipate that its existing business, the LPG Transportation Business (see below), will generate sufficient cash flow to increase unitholder value.  Therefore, the General Partner of Rio Vista intends to use a portion of its available cash and credit to make strategic acquisitions.  There can be no assurance, however, that Rio Vista will be able to complete such acquisitions or that, if completed, such acquisitions will increase unitholder value.  See “Risk Factors” below.

Rio Vista's principal executive offices are located at 820 Gessner Road, Suite 1285, Houston, Texas 77024, and its telephone number is (713) 467-8235.