| 4301 | C Bar Petroleum Company | Lubbock, TX 79413 | Oil & Gas Operator | May 2018 |
| 4302 | C C & S Oil Oper | | Oil Operator | Apr 1983 |
| 4303 | C C Co | Holladay, UT 84124 | Oil & Gas Operator | Jan 2020 |
| 4304 | C D Oil | Wellsville, KS 66092 | Oil Operator | Aug 1998 |
| 4305 | C D Operating Company Inc | Oklahoma City, OK 73116 | Oil & Gas Operator | Apr 2015 |
| 4306 | C E D LC | Enid, OK 73702-0326 | Oil & Gas Operator | Oct 2021 |
| 4307 | C E Energy LLC | Katy, TX 77449 | Oil Operator | Jun 2026 |
| 4308 | C E Harmon Oil Inc | Tulsa, OK 74136-6559 | Oil & Gas Operator | Apr 2026 |
| 4309 | C E L Inc | Bartlesville, OK 74006 | Oil & Gas Operator | Jan 2020 |
| 4310 | C E Larue & B M Muncy Jr | Artesia, NM 882111370 | Oil & Gas Operator | Jun 2006 |
| 4311 | C E Staples | Dallas, TX 75205 | Oil & Gas Operator | Jul 1995 |
| 4312 | C F & L Producing Co | | Oil & Gas Operator | Sep 2000 |
| 4313 | C F M Oil Co Dba Louis And Judy Fulton | Artesia, NM 88210 | Oil & Gas Operator | May 2011 |
| 4314 | C F Oil - Frazie | | Oil Operator | Dec 1994 |
| 4315 | C G Davis, Et Al | | Oil & Gas Operator | Mar 1986 |
| 4316 | C G G Oil Co | | Oil & Gas Operator | Dec 2006 |
| 4317 | C G O Inc | Wheeling, WV 26003 | Oil & Gas Operator | Dec 2024 |
| 4318 | C G Oil, Inc. | Victoria, KS 67671 | Oil Operator | Feb 2026 |
| 4319 | C H E Company Inc | Shawnee, OK 74801 | Oil Operator | Feb 2012 |
| 4320 | C H K Oil, LLC | Stephens, AR 71764 | Oil Operator | Jan 2025 |
| 4321 | C K Oil Company | Great Bend, KS 67530 | Oil & Gas Operator | Feb 2026 |
| 4322 | C L & S Oil Company Inc | Perry, OK 73077-0841 | Oil & Gas Operator | Jan 2018 |
| 4323 | C L Conner | Humble, TX 77338 | Oil & Gas Operator | Oct 2025 |
| 4324 | C M F Oil LLC | | Oil Operator | Apr 2026 |
| 4325 | C M S Gas Transmission Co | | Oil & Gas Operator | Dec 2020 |
| 4326 | C M S Oil And Gas Co And Miller Brothers | | Oil & Gas Operator | Apr 1992 |
| 4327 | C M T Petroleum | | Oil Operator | Jul 1995 |
| 4328 | C M X Incorporat | | Oil & Gas Operator | Dec 1996 |
| 4329 | C N B Enterprises | Yates Center, KS 66783 | Oil & Gas Operator | Jan 2009 |
| 4330 | C N Operating Co | Drumright, OK 74030 | Oil & Gas Operator | Nov 1998 |
| 4331 | C O Fulton | Artesia, NM 88211 | Oil & Gas Operator | Sep 2022 |
| 4332 | C O G Company | Bangs, TX 76823 | Oil & Gas Operator | Jun 2026 |
| 4333 | C Oil Co. | New Braunfels, TX 78132 | Oil & Gas Operator | Feb 2017 |
| 4334 | C R A C O Incorp | | Oil Operator | May 1988 |
| 4335 | C R I Inc | Midland, TX 79702 | Oil & Gas Operator | Nov 1993 |
| 4336 | C Rose Oil Co. | Midland, TX 79708 | Oil & Gas Operator | Apr 2026 |
| 4337 | C S J, Inc. | Austin, TX 78716 | Oil & Gas Operator | Jun 2026 |
| 4338 | C S Petroleum Inc | Norman, OK 73070 | Oil & Gas Operator | Dec 2024 |
| 4339 | C T R Resources Inc | Alliance, OH 44601 | Oil & Gas Operator | Dec 2013 |
| 4340 | C W Oil Producer | | Oil Operator | Oct 1998 |
| 4341 | C W Riggs Inc | St. Marys, WV 26170 | Oil & Gas Operator | Dec 1999 |
| 4342 | C W Trainer | Midland, TX 79702 | Oil & Gas Operator | Nov 2009 |
| 4343 | C&C II | Pleasanton, TX 78064 | Oil & Gas Operator | Mar 1998 |
| 4344 | C&D Management Company Dba Freedom Ventures | Las Vegas, NV 89149 | Oil & Gas Operator | Feb 2019 |
| 4345 | C&M Operating Company, LLC | | Oil & Gas Operator | Apr 2011 |
| 4346 | C&P Resources Operating Co,LLC | Houston, TX 77056 | Oil & Gas Operator | Jun 2026 |
| 4347 | C-D Oil Company, Inc. | Cameron, TX 76520 | Oil Operator | Jun 2026 |
| 4348 | C-V Oil Company | Memphis, TN 38103 | Oil Operator | Jun 1998 |
| 4349 | C-Water Disposal Inc | Oklahoma City, OK 73116-7326 | Oil Operator | Dec 2014 |
| 4350 | C. A. Cardneaux, Inc. | | Oil & Gas Operator | Apr 1990 |
| 4351 | C. C. Killingsworth Opr. | | Oil Operator | Dec 1999 |
| 4352 | C. Case Company | | Oil & Gas Operator | Feb 2026 |
| 4353 | C. D. Oil, Inc. | Wellsville, KS 66092 | Oil Operator | Dec 2009 |
| 4354 | C. D. Pierce | | Oil Operator | Mar 1991 |
| 4355 | C. E. Allen Co. Inc. | | Oil & Gas Operator | Mar 2026 |
| 4356 | C. E. Braly | | Oil & Gas Operator | Dec 1991 |
| 4357 | C. F. Oil, A General Partnership | Lake Lotawana, MO 64086 | Oil Operator | Nov 2025 |
| 4358 | C. F. Sudduth | | Oil & Gas Operator | Dec 1988 |
| 4359 | C. H. C. Gerard | | Oil & Gas Operator | Jan 2025 |
| 4360 | C. H. Todd, Inc. | Wichita, KS 67212 | Oil & Gas Operator | Dec 2019 |
| 4361 | C. I. McKown & Son, Inc. | Newton, WV 25266-0711 | Oil & Gas Operator | Dec 2021 |
| 4362 | C. J. Broome Oil Company | | Oil & Gas Operator | Jan 2020 |
| 4363 | C. J. Services | | Oil & Gas Operator | Sep 2016 |
| 4364 | C. L. Brown, III | | Oil Operator | Dec 1991 |
| 4365 | C. L. Brown, Inc. | | Oil Operator | Dec 1999 |
| 4366 | C. L. Morris | | Oil Operator | Feb 2004 |
| 4367 | C. L. Morris, Inc. | | Oil & Gas Operator | Feb 2004 |
| 4368 | C. M. Frizzell | | Oil & Gas Operator | Mar 2014 |
| 4369 | C. M. Oil Corporation | Corpus Christ, TX 78401 | Oil & Gas Operator | Mar 2016 |
| 4370 | C. M. Roberson | | Oil Operator | Jun 1984 |
| 4371 | C. O. Oil And Gas, LLC | Pampa, TX 79066 | Oil & Gas Operator | Jun 2026 |
| 4372 | C. Smith & Associates, Inc. | | Oil Operator | Aug 1991 |
| 4373 | C. T. & Ted Paul | | Oil Operator | Mar 2019 |
| 4374 | C. V. Radke | | Oil Operator | Jan 1993 |
| 4375 | C. W. Brumley | | Oil & Gas Operator | Jun 2006 |
| 4376 | C. W. Resources, Inc. | Longview, TX 75604 | Oil & Gas Operator | Oct 2025 |
| 4377 | C. Wayland Brooks | | Oil & Gas Operator | Dec 1987 |
| 4378 | C.B.C. Producing Co. | | Oil & Gas Operator | Jul 1989 |
| 4379 | C.F. Braun & Company | | Oil & Gas Operator | Dec 1986 |
| 4380 | C.F.D. Inc. | | Oil & Gas Operator | Nov 1988 |
| 4381 | C.F.O., Inc. | Liberty, TX 77575 | Oil Operator | Jun 2026 |
| 4382 | C.J. Oil Company | Iowa Park, TX 76367 | Oil Operator | Jan 2025 |
| 4383 | C.O.W. Operating Company | Graham, TX 76450 | Oil Operator | Jun 2026 |
| 4384 | C.P.I. | | Oil & Gas Operator | Oct 2007 |
| 4385 | C.S.V. Oil Exploration Co | West Jordan, UT 84088 | Gas Operator | Mar 2026 |
| 4386 | C.T.R. Oil, Inc. | | Oil & Gas Operator | Jan 2025 |
| 4387 | C.W. Pickering, Inc. | Victoria, TX 77904 | Gas Operator | Sep 2022 |
| 4388 | C.W.F.K., Inc. | | Gas Operator | Dec 1986 |
| 4389 | C12 Energy: North Dakota LLC | | Oil Operator | Apr 2017 |
| 4390 | C12 Kansas Oil, LLC | Denver, CO 80202 | Oil Operator | Dec 2009 |
| 4391 | C3oil, LLC | New Strawn, KS 66839 | Oil Operator | Feb 2026 |
| 4392 | C5 Energy LLC | Collinsville, OK 74021 | Oil & Gas Operator | Dec 2019 |
| 4393 | C6 Operating, L.L.C. | Keatchie, LA 71046 | Oil & Gas Operator | Jun 2026 |
| 4394 | Caac 100 LLC | | Oil & Gas Operator | Mar 2026 |
| 4395 | Cab Resources, LLC | Odessa, TX 79762 | Oil Operator | Jun 2026 |
| 4396 | Caba, LLC | | Oil Operator | Jan 2025 |
| 4397 | Cabal Energy Corporation | Midland, TX 79701 | Oil & Gas Operator | Jun 2026 |
| 4398 | Caballero Operations LLC | | Oil & Gas Operator | Feb 2026 |
| 4399 | Cabana Oil Corp. | Abilene, TX 79608 | Oil & Gas Operator | Feb 2006 |
| 4400 | Cabeza Oil And Gas, LLC | Austin, CO 81410 | Oil & Gas Operator | Mar 2022 |