Penny Petroleum Corporation

On October 2, 2007, Rio Vista, together with Rio Vista Penny LLC, an Oklahoma limited liability company (Rio Vista Penny),  entered into an Asset Purchase Agreement (Penny Agreement) with Penny Petroleum Corporation, an Oklahoma corporation (Penny Petroleum), and Gary Moores, a shareholder of Penny Petroleum.  The Penny Agreement is effective as of October 1, 2007, and has been amended pursuant to an Amendment to Asset Purchase Agreement between the parties dated as of October 25, 2007 (as amended, Amended Penny Agreement).  The Amended Penny Agreement provides for Rio Vista Penny to acquire the real and personal property interests of Penny Petroleum in certain oil and gas properties located in McIntosh, Pittsburg and Haskell counties in Oklahoma, including approximately 66.66% of the outstanding capital stock of MV Pipeline Company, an Oklahoma corporation (collectively, the Penny Assets).  The total purchase price for the Penny Assets is $7,400,000, consisting of cash and equity interests in Rio Vista. The cash portion of the purchase price is payable with $6,400,000 due at closing, together with a promissory note from Rio Vista with the principal amount of $500,000 bearing interest at 7% per annum (the Penny Note) payable to Penny Petroleum with a maturity date six months from the closing.  Beginning three months after the closing, Penny Petroleum has the option to convert the outstanding principal and interest of the Penny Note into common units of Rio Vista at a conversion price equal to 90% of the 10-day average closing price of such common units as reported by the NASDAQ Stock Market at the time of conversion.  The conversion option may be exercised on only one occasion and expires on the maturity date of the Penny Note.  Rio Vista Penny paid to Penny Petroleum an initial deposit in the amount of $740,000 upon execution of the Penny Agreement and an additional deposit in the amount of $740,000 on October 22, 2007  (collectively, the Penny Deposits).  The Penny Deposits will be credited to the purchase price upon closing of the transaction but are not refundable to Rio Vista Penny if the transaction does not close for any reason.  The equity portion of the purchase price is payable by delivery of 45,998 common units of Rio Vista (the Penny Units). Rio Vista has agreed to file with the Securities and Exchange Commission (SEC) a registration statement on Form S-3 covering the Penny Units within 90 days following the closing date of the Penny Agreement.  The Amended Penny Agreement contains customary representations, warranties and covenants of the parties and is subject to customary conditions to closing, including Rio Vista Penny’s satisfaction with its due diligence review of the Penny Assets.  Rio Vista Penny may terminate the Amended Penny Agreement if it determines for any reason that it is not feasible to proceed with the transactions contemplated by the agreement (subject to forfeiture of the Penny Deposits).  If the transactions are not completed by November 19, 2007, Penny Petroleum may terminate the Amended Penny Agreement and retain the Penny Deposits.

GO, LLC

On October 2, 2007, Rio Vista, together with its newly-formed, wholly-owned subsidiary, Rio Vista GO LLC, an Oklahoma limited liability company (Rio Vista GO), entered into a Stock Purchase Agreement (GO Agreement) with GO, LLC, an Oklahoma limited liability company (GO), Outback Production, Inc., a Nevada corporation (Outback), which is the owner of all of the outstanding membership interests of GO, and Gary Moores and Bill Wood, each a shareholder of Outback.  The GO Agreement is effective as of October 2, 2007.  The GO Agreement provides for Rio Vista GO to acquire all of the membership interests of GO, which operates an oil and gas pipeline business located in Pittsburg and Haskell counties in Oklahoma (the GO Assets).   The total purchase price for the membership interests of GO is $4,000,000, consisting of cash and equity interests in Rio Vista.  The cash portion of the purchase price is payable with $3,000,000 due at closing.  Rio Vista GO paid to Outback an initial deposit in the amount of $400,000 upon execution of the GO Agreement and an additional deposit in the amount of $400,000 on October 22, 2007  (collectively, the GO Deposits).  The GO Deposits will be credited to the purchase price upon closing of the transaction but are not refundable to Rio Vista GO if the transaction does not close for any reason.  The equity portion of the purchase price is payable by delivery of 91,996 common units of Rio Vista (the GO Units).  Rio Vista has agreed to file with the SEC a registration statement on Form S-3 (the GO Registration Statement) covering the GO Units within 90 days following the closing date of the GO Agreement.  The GO Agreement contains customary representations, warranties and covenants of the parties and is subject to customary conditions to closing, including Rio Vista GO’s satisfaction with its due diligence review of GO and the GO Assets.  Rio Vista may terminate the GO Agreement if it determines for any reason that it is not feasible to proceed with the transactions contemplated by the agreement (subject to forfeiture of the GO Deposits).  If the transactions are not completed by November 19, 2007, Outback may terminate the GO Agreement and retain the GO Deposits. 

On the date the GO Registration Statement is declared effective by the SEC (the Registration Date), if the closing price of Rio Vista’s common units as reported by the NASDAQ Stock Market (the Registration Date Price) is less than 80% of such price as so reported on the closing date (the Closing Date Price),  Outback shall have the option for a period of 30 days to rescind the transactions contemplated by the GO Agreement unless Rio Vista GO agrees to deliver to Outback either (i) additional common units of Rio Vista (the Additional GO Units) in such number as necessary so that the total value of the GO Units and the Additional GO Units, in each case based on the Registration Date Price, is at least 80% of the value of the Purchase Price Units based on the Closing Date Price or (ii) additional cash (the Additional Cash) in such amount as necessary so that the total value of the GO Units, based on the Registration Date Price, together with the Additional Cash, is at least 80% of the value of the GO Units based on the Closing Date Price.  In lieu of delivery of Additional GO Units or Additional Cash to supplement the GO Units, Rio Vista GO shall have the alternate option to pay the entire value of the GO Units based on the Closing Date Price in cash (the All Cash Payment), provided that Rio Vista GO makes the All Cash Payment in full within 10 business days following an election by Outback to rescind as provided above.  Upon delivery of the All Cash Payment to the Seller, all GO Units shall be returned to Rio Vista GO and/or cancelled by Rio Vista.

Rio Vista has agreed to guarantee (as a primary obligor) all of the obligations of Rio Vista GO under the GO Agreement. 

LPG Transportation Agreement

Under the Rio Vista Restated PSA and the related transportation agreement between Rio Vista and TransMontaigne dated August 22, 2006 (LPG Transportation Agreement), TransMontaigne agreed to exclusively use the services and Retained Assets of Rio Vista on a fee basis for purposes of transportation of LPG to be delivered into northeastern Mexico and/or LPG sold pursuant to the existing PMI agreement.  Rio Vista has agreed not to transport LPG through Rio Vista’s Retained Assets in Mexico except on behalf of TransMontaigne, subject to certain conditions. TransMontaigne has agreed to use the Retained Assets pursuant to the LPG Transportation Agreement which began on August 22, 2006 and runs for the term of the existing PMI agreement between TransMontaigne and PMI, as extended from time to time thereafter.  The Company receives a fee for all LPG transported on behalf of TransMontaigne through the Retained Assets.  In addition, under the Rio Vista Restated PSA and the related pipeline services agreement between Rio Vista and TransMontaigne dated August 22, 2006 (U.S. Pipeline Services Agreement), TransMontaigne agreed to provide routine and non-routine operation and maintenance services, as defined, for the U.S. portion only of Rio Vista’s pipelines between Brownsville, Texas and Matamoros, Mexico.  TransMontaigne agreed to provide the routine services at its sole cost and expense.  For the non-routine services, Rio Vista agreed to reimburse TransMontaigne for all costs actually incurred in performing the services and all materials and supplies provided in connection with such services, plus 15%.