EXHIBIT 21.1 DIRECT SUBSIDIARIES OF THE REGISTRANT NAME OF STATE/JURISDICTION OF NAME UNDER WHICH PERCENTAGE SUBSIDIARY INCORPORATION/ORGANIZATION BUSINESS IS CONDUCTED INTEREST OWNED MGV Energy Inc. Canada MGV Energy Inc. 100 Mercury Michigan, Inc. Michigan Mercury Michigan, Inc. 100 Beaver Pipeline, L.L.C. Michigan Beaver Pipeline, L.L.C. 50* Cinnabar Energy Michigan Cinnabar Energy Services & 50* Services & Trading, LLC Trading, LLC Terra Energy Ltd. Michigan Terra Energy Ltd. 100 GTG Pipeline Corporation Virginia GTG Pipeline Corporation 100 INDIRECT SUBSIDIARIES OF THE REGISTRANT 1. Direct Subsidiaries of Terra Energy Ltd. NAME OF STATE/JURISDICTION OF NAME UNDER WHICH PERCENTAGE SUBSIDIARY INCORPORATION/ORGANIZATION BUSINESS IS CONDUCTED INTEREST OWNED Energy Acquisition Michigan Energy Acquisition Operating 100 Operating Corporation Corporation Kristen Corporation Michigan Kristen Corporation 100 Terra Pipeline Company Michigan Terra Pipeline Company 100 2. Direct Subsidiaries of Mercury Michigan, Inc. NAME OF STATE/JURISDICTION OF NAME UNDER WHICH PERCENTAGE SUBSIDIARY INCORPORATION/ORGANIZATION BUSINESS IS CONDUCTED INTEREST OWNED Beaver Pipeline, L.L.C. Michigan Beaver Pipeline, L.L.C. 50* Cinnabar Energy Services & Michigan Cinnabar Energy Services & 50* Trading, LLC Trading, LLC * 100% of this entity is owned by the registrant, 50% directly and 50% indirectly through Mercury Michigan, Inc.