| 5001 | Castle Rock Oil LLC | | Oil Operator | Feb 2026 |
| 5002 | Castle-Rock Prod | | Oil Operator | Mar 1992 |
| 5003 | Castlerock Ef Operating LLC | San Antonio, TX 78232 | Oil & Gas Operator | May 2026 |
| 5004 | Castlerock Oil Company, Inc. | Addison, TX 75001 | Oil & Gas Operator | Feb 2006 |
| 5005 | Castlerock Operating, LLC | San Antonio, TX 78232 | Oil & Gas Operator | Dec 2020 |
| 5006 | Castlerock Resources Inc | Oklahoma City, OK 73116-3710 | Oil & Gas Operator | Jul 2020 |
| 5007 | Castor Exploration, Inc. | | Oil & Gas Operator | Dec 1991 |
| 5008 | Castor Production, L.L.C. | | Oil Operator | Dec 2024 |
| 5009 | Caswell Bros. Oil Co. | Bowie, TX 76230 | Oil & Gas Operator | May 2026 |
| 5010 | Cat Canyon Resources LLC | | Oil & Gas Operator | Dec 2025 |
| 5011 | Cat Creek Holdings LLC | Winnett, MT 59087 | Oil Operator | Jan 2026 |
| 5012 | Cat Energy, LLC | Galva, KS 67443 | Oil Operator | Aug 2008 |
| 5013 | Cat Oil | Byron, WY 82412 | Oil Operator | May 2001 |
| 5014 | Cat-Oil Inc. | | Oil Operator | Nov 2015 |
| 5015 | Catalyst Energy Inc | Pittsburgh, PA 15218 | Oil & Gas Operator | Feb 2026 |
| 5016 | Catamount Energy Partners LLC | Denver, CO 80202 | Gas Operator | Mar 2026 |
| 5017 | Catamount Resources, Inc. | Grafton, WV 26354-0000 | Gas Operator | Dec 2009 |
| 5018 | Catarina Petroleum L. C. | Dallas, TX 75228 | Oil & Gas Operator | Jun 2008 |
| 5019 | Catena Resources Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2022 |
| 5020 | Cates Betty J | Tulsa, OK 74112 | Oil & Gas Operator | Nov 2016 |
| 5021 | Catfish Minerals LLC | Dallas, TX 75240 | Oil & Gas Operator | Sep 2014 |
| 5022 | Catfish Oil | | Oil Operator | Nov 2025 |
| 5023 | Cather Rogers Barnes & Cree | | Oil & Gas Operator | Dec 2009 |
| 5024 | Cather, Barnes & Cree | | Oil & Gas Operator | Dec 2009 |
| 5025 | Cather-Herley Oil Company | | Oil & Gas Operator | Mar 2026 |
| 5026 | Cathexis Oil & Gas, LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2014 |
| 5027 | Cathey Oil, Inc. | | Oil & Gas Operator | Aug 2009 |
| 5028 | Cathey Petroleum Company, Inc. | Big Spring, TX 79720 | Oil & Gas Operator | Apr 2008 |
| 5029 | Cathey Production Company | Ryan, OK 73565-0485 | Oil Operator | Dec 2010 |
| 5030 | Caths Oil & Gas | Midland, TX 79706 | Oil & Gas Operator | May 2026 |
| 5031 | Catlett & Ferguson-Carl O & G | | Oil & Gas Operator | Jun 1978 |
| 5032 | Catlin Drilling Company | Iowa Park, TX 76367 | Oil & Gas Operator | Aug 2003 |
| 5033 | Catlin, Carl | Jacksboro, TX 76458 | Oil & Gas Operator | Mar 2008 |
| 5034 | Catlin, Cecil | Iowa Park, TX 76367 | Oil & Gas Operator | Dec 1995 |
| 5035 | Catlin, Cecil, Oil Co. | Iowa Park, TX 76367 | Oil & Gas Operator | Jun 2000 |
| 5036 | Catlin, Delbert | Iowa Park, TX 76367 | Oil & Gas Operator | May 2026 |
| 5037 | Catlin, Randy | Iowa Park, TX 76367 | Oil Operator | May 2026 |
| 5038 | Catoilan Corporation | Midland, TX 79702 | Oil & Gas Operator | May 2026 |
| 5039 | Catron Oil Div - | | Oil Operator | Aug 1989 |
| 5040 | Catron Oil Division | | Oil Operator | Feb 2000 |
| 5041 | Catron, Jeffery V | | Oil Operator | Dec 2024 |
| 5042 | Catt Drilling Co. | Holyrood, KS 67450 | Oil Operator | Aug 1989 |
| 5043 | Cattlemans Oil O | | Oil Operator | Nov 1995 |
| 5044 | Cattlemans Oil Operations | | Oil Operator | Dec 2009 |
| 5045 | Cattlemans Oil Operations LLC | Hays, KS 67601 | Oil Operator | Dec 2019 |
| 5046 | Caturus Energy, LLC | Houston, TX 77024 | Oil & Gas Operator | May 2026 |
| 5047 | Caulkins Oil Company | Aztec, NM 87410 | Oil & Gas Operator | Oct 2024 |
| 5048 | Cavalcade Operating Company LLC | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2017 |
| 5049 | Cavalier Oil & Gas, Inc. | Buchanan Dam, TX 78609 | Oil & Gas Operator | May 2026 |
| 5050 | Cavalier Oil Co. Et Al | | Oil Operator | Jan 1986 |
| 5051 | Cavalier Petroleum | Shelby, MT 59474 | Oil & Gas Operator | Oct 2014 |
| 5052 | Cavalry Resources LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Jun 2010 |
| 5053 | Cavendish Petro Of Oh Inc | Zanesville, OH 43701 | Oil & Gas Operator | Dec 1989 |
| 5054 | Cavenham Energy Resources Inc. | | Oil & Gas Operator | Apr 1991 |
| 5055 | Cavenham Energy Resrces Inc JV | | Oil Operator | Mar 1991 |
| 5056 | Cavenham Forest Ind., Inc. | | Oil & Gas Operator | Nov 1987 |
| 5057 | Cavenham Forest Ind., Inc. J V | | Oil Operator | Nov 1987 |
| 5058 | Cavilla Energy, Inc. | Longview, TX 75606 | Oil Operator | May 2026 |
| 5059 | Cavillo Oil Company LC Of Texas | Marshall, TX 75671 | Oil & Gas Operator | May 2026 |
| 5060 | Cavillo Oil Corporation | Marshall, TX 75670 | Oil & Gas Operator | Jun 1998 |
| 5061 | Cavins Oilfield Services, LLC. | | Oil Operator | Apr 2006 |
| 5062 | Caw Prop LP | Dayton, PA 16222-1624 | Gas Operator | Dec 2025 |
| 5063 | Cawell Energy, LLC | Spring, TX 77379 | Oil Operator | May 2026 |
| 5064 | Cayman Exploration Corp | Tulsa, OK 74119-1323 | Oil & Gas Operator | Jun 2001 |
| 5065 | Cayman Resources Corporation | Tulsa, OK 74119-1323 | Oil & Gas Operator | Jun 2001 |
| 5066 | Caza Exploration Company | | Oil Operator | Nov 1991 |
| 5067 | Caza Operating, LLC | Midland, TX 79701 | Oil & Gas Operator | May 2026 |
| 5068 | Cazador Operating, LLC | Midland, TX 79702 | Oil & Gas Operator | May 2026 |
| 5069 | Cazar Energy Inc | Austin, TX 78734 | Oil & Gas Operator | May 2026 |
| 5070 | CB Energy, LLC | Houston, TX 77024 | Oil & Gas Operator | Nov 2017 |
| 5071 | CB Oil Company | Drumright, OK 74030 | Oil & Gas Operator | Jan 2026 |
| 5072 | Cbase Corporation | | Oil & Gas Operator | Mar 2026 |
| 5073 | CBL Resources LLC | Tulsa, OK 74136-6308 | Oil & Gas Operator | Jan 2026 |
| 5074 | CBM Gas Company LLC | Dewey, OK 74029 | Oil & Gas Operator | Aug 2020 |
| 5075 | CBM Partners Corporation | Overland Park, KS 66221 | Oil Operator | Aug 2015 |
| 5076 | Cbmoncrief Operating, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | May 2026 |
| 5077 | CBN Operating Corp. | Austin, TX 78746 | Oil & Gas Operator | May 2026 |
| 5078 | Cbo Oil And Gas, LLC | Stillwater, OK 74075-8793 | Oil & Gas Operator | Jan 2026 |
| 5079 | CBR Oil Company | Lytle, TX 78052 | Oil & Gas Operator | Jul 1997 |
| 5080 | CBS Energy LLC | Oklahoma City, OK 73142-4437 | Oil & Gas Operator | Feb 2026 |
| 5081 | CBS Operating Corp | Midland, TX 79702 | Oil & Gas Operator | Aug 2012 |
| 5082 | CCF, Inc. | Snyder, TX 79550 | Oil & Gas Operator | Apr 1998 |
| 5083 | CCGM Exploration & Prod.,L.C. | Austin, TX 78738 | Oil & Gas Operator | May 2026 |
| 5084 | Cci East Texas Upstream LLC | Houston, TX 77002 | Oil & Gas Operator | Jan 2021 |
| 5085 | Cci Gulf Coast Upstream LLC | Teague, TX 75860 | Oil & Gas Operator | Mar 2021 |
| 5086 | Cci Robinson'S Bend LLC | | Gas Operator | Feb 2026 |
| 5087 | CCM Enterprises, Inc | | Oil & Gas Operator | Oct 1985 |
| 5088 | CCRP Operating Inc | Denver, CO 80202 | Oil & Gas Operator | Aug 2024 |
| 5089 | CCS Investments Inc | Bartlesville, OK 74006-1941 | Oil Operator | Feb 2026 |
| 5090 | CCV, Inc. | Houston, TX 77019 | Oil & Gas Operator | Sep 1994 |
| 5091 | CD Consulting & Operating Co. | Bridgeport, TX 76426 | Oil & Gas Operator | May 2026 |
| 5092 | CD Resources Company | San Antonio, TX 78217 | Oil & Gas Operator | Mar 2002 |
| 5093 | CDC Oil, LLC | Chanute, KS 66720 | Oil Operator | Nov 2025 |
| 5094 | CDC Operating Company | Dallas, TX 75218 | Oil & Gas Operator | May 2026 |
| 5095 | CDG Inc | Sapulpa, OK 74066-6339 | Oil Operator | Oct 2020 |
| 5096 | CDJ Oil Co. | Albany, TX 76430 | Oil & Gas Operator | Jul 2025 |
| 5097 | CDJ Oil Company, LLC | Albany, TX 76430 | Oil & Gas Operator | May 2026 |
| 5098 | CDM Oil & Gas | | Oil & Gas Operator | Apr 2017 |
| 5099 | CDS Oil Company | Tulsa, OK 74147-1514 | Oil & Gas Operator | Mar 2015 |
| 5100 | CDX Gas, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Oct 2009 |