EX-21 11 c83834exv21.htm EXHIBIT 21 Exhibit 21
Exhibit 21
SUBSIDIARIES OF THE REGISTRANT
         
Name of Subsidiaries   State of Organization   Trade Names
 
        
Penn Wilson CNG, Inc.
  Delaware   None
Penn CNG Holdings, Inc.
  Delaware   None
Penn Octane International, L.L.C.
  Delaware   None
Rio Vista Energy Partners L.P.
  Delaware   None
Rio Vista GP LLC
  Delaware   None
Rio Vista Operating GP LLC
  Delaware   None
Rio Vista Operating Partnership L.P.
  Delaware   None
Rio Vista E & P, L.L.C.
  Oklahoma   None
Rio Vista Eco, L.L.C.
  Oklahoma   None
Rio Vista GO, L.L.C.
  Oklahoma   None
Rio Vista Penny, L.L.C.
  Oklahoma   None
Rio Vista Operating, L.L.C.
  Oklahoma   None
MV Pipeline Company
  Oklahoma   None
Regional Enterprises, Inc.
  Virginia   None