| 401 | Campana Petroleum Company | Midland, TX 79705 | Oil & Gas Operator | Jun 2026 |
| 402 | Campanella, George L | Great Falls, MT 59403 | Oil & Gas Operator | Jan 2026 |
| 403 | Campbell & Assoc.-Ring | | Oil Operator | Nov 1980 |
| 404 | Campbell & Associates | | Oil & Gas Operator | Aug 1987 |
| 405 | Campbell & Hedrick | Midland, TX 79702 | Oil & Gas Operator | Jun 2014 |
| 406 | Campbell B R | Ardmore, OK 73401 | Oil & Gas Operator | Oct 2002 |
| 407 | Campbell Co. Et Al | | Oil Operator | Apr 1986 |
| 408 | Campbell Dale H | McKeesport, PA 15135-3307 | Gas Operator | Dec 2017 |
| 409 | Campbell Don G | Konawa, OK 74849 | Oil Operator | Feb 1997 |
| 410 | Campbell Energy Corporation | | Oil & Gas Operator | May 1992 |
| 411 | Campbell Energy LLC | Carmi, IL 62821 | Oil Operator | Jan 2026 |
| 412 | Campbell Oil & Gas Inc | Indiana, PA 15701-0278 | Oil & Gas Operator | Mar 2026 |
| 413 | Campbell Production Company | Tulsa, OK 74137-4145 | Oil & Gas Operator | Mar 2015 |
| 414 | Campbell Robert | | Oil & Gas Operator | Aug 1990 |
| 415 | Campbell Wells Corporation | | Oil Operator | Dec 1995 |
| 416 | Campbell, G S | Park City, UT 84060 | Oil & Gas Operator | Apr 1991 |
| 417 | Campbell, George M. | Lubbock, TX 79490 | Oil & Gas Operator | Apr 2003 |
| 418 | Campbell, Robert E. | Wichita, KS 67206 | Oil & Gas Operator | May 2019 |
| 419 | Campbell, T. K. | Fort Worth, TX 76118 | Oil & Gas Operator | Mar 2006 |
| 420 | Campground Corporation | | Oil Operator | Nov 2023 |
| 421 | Camphire George E. | Danville, OH 43014 | Oil & Gas Operator | Dec 2024 |
| 422 | Camplin, Raymond | Greenville, KY 42345 | Oil Operator | Dec 2018 |
| 423 | Campo Verde Oil Inc. | | Oil Operator | Mar 2026 |
| 424 | Campsey Minerals | Jacksboro, TX 76458 | Oil & Gas Operator | Jun 2026 |
| 425 | Camterra Resources, Inc. | Marshall, TX 75671 | Oil & Gas Operator | Jun 2026 |
| 426 | Camtex Industries Inc. | | Oil Operator | Dec 1996 |
| 427 | Camwest II LP | McKinney, TX 75070 | Oil & Gas Operator | Jul 2007 |
| 428 | Camwest Limited Partnership | Denver, CO 80202 | Oil & Gas Operator | Apr 2004 |
| 429 | Can Do Enterprises | | Oil Operator | Dec 2024 |
| 430 | Can'T Complain Operating Co. | Georgetown, TX 78633 | Oil & Gas Operator | Jun 2026 |
| 431 | Can-Tex Energy Corp. | Dallas, TX 75231 | Oil & Gas Operator | Nov 2003 |
| 432 | Canaan Energy Corporation | Oklahoma City, OK 73154-8806 | Oil & Gas Operator | Mar 2015 |
| 433 | Canaan Exploration Inc | Oklahoma City, OK 73123 | Oil & Gas Operator | Jan 1998 |
| 434 | Canaan Petroleum Inc | San Antonio, TX 78230 | Oil & Gas Operator | Dec 2025 |
| 435 | Canaan Producing LLC | Burbank, OH 44214 | Oil & Gas Operator | Dec 2025 |
| 436 | Canaan Resources LLC | Oklahoma City, OK 73118-1126 | Gas Operator | Oct 2023 |
| 437 | Canaan Resources X LLC | Oklahoma City, OK 73103-4925 | Oil & Gas Operator | Sep 2024 |
| 438 | Canada Crown Inv Corporation | | Oil & Gas Operator | Apr 1998 |
| 439 | Canaday Oil Corp | Goddard, KS 67052 | Oil & Gas Operator | Feb 2026 |
| 440 | Canan Mowrey Operating, LLC | Wichita Falls, TX 76308 | Oil & Gas Operator | Jun 2026 |
| 441 | Canan Operating, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Jun 2026 |
| 442 | Canard Colvert Operating LLC | Dallas, TX 75231 | Oil & Gas Operator | Feb 2026 |
| 443 | Candelero Oil & Gas Company | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 444 | Candice Venture #1 | | Oil & Gas Operator | May 1992 |
| 445 | Candleridge Oil, Inc. | Fort Worth, TX 76109 | Oil & Gas Operator | Jun 2003 |
| 446 | Candy Oil Production | Sand Springs, OK 74063-3410 | Oil Operator | Feb 2017 |
| 447 | Cane Creek Energy Partners Inc | Morris, OK 74445 | Oil & Gas Operator | Feb 2026 |
| 448 | Cane Creek Energy, LLC | Charleston, WV 25314 | Oil & Gas Operator | Dec 2021 |
| 449 | Canest, LLC | Lake Oswego, OR 97035 | Gas Operator | Dec 2006 |
| 450 | Canfield Oil & Gas Co | Allentown, PA 18103-9667 | Oil & Gas Operator | Dec 2025 |
| 451 | Cankton Oil Company | | Oil Operator | May 1985 |
| 452 | Canlan Oil Company | | Oil & Gas Operator | Mar 1992 |
| 453 | Cannan Calvin B | | Oil Operator | Jul 1991 |
| 454 | Cannan, Morris | San Antonio, TX 78205 | Oil & Gas Operator | Jun 2026 |
| 455 | Cannon | Grand Junction, CO 81502 | Oil Operator | Mar 2026 |
| 456 | Cannon Oil Co. | | Oil Operator | Dec 2009 |
| 457 | Cannon Operating Company LLC | Garland, TX 75043 | Oil Operator | Jun 2026 |
| 458 | Cannon, Robert D. | | Oil & Gas Operator | Dec 2022 |
| 459 | Cannuck Resources Inc | Nowata, OK 74048 | Oil & Gas Operator | Aug 2000 |
| 460 | Cano Petro Of New Mexico, Inc. | Tulsa, OK 74159 | Oil & Gas Operator | Mar 2019 |
| 461 | Canok International Inc | Okmulgee, OK 74447 | Oil & Gas Operator | Feb 2026 |
| 462 | Canstar Oil & Gas, Inc. | | Oil & Gas Operator | Dec 1994 |
| 463 | Cantera Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Nov 2017 |
| 464 | Cantium, LLC | | Oil & Gas Operator | Dec 2024 |
| 465 | Canton Oil & Gas Co | Pleasantville, PA 16341-1729 | Oil & Gas Operator | Dec 2004 |
| 466 | Cantrell Energy Corporation | Ada, OK 74820-0835 | Oil & Gas Operator | Mar 2026 |
| 467 | Cantrell Oil Co. | Elbert, TX 76359 | Oil & Gas Operator | Aug 2003 |
| 468 | Cantrell Robert R | Ada, OK 74820 | Oil & Gas Operator | Feb 2026 |
| 469 | Cantro Exploration, Inc. | San Antonio, TX 78270 | Oil & Gas Operator | May 2000 |
| 470 | Cantu Operating, LLC | McAllen, TX 78504 | Oil Operator | Jun 2026 |
| 471 | Canvas Energy LLC | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2026 |
| 472 | Canyon Creek Energy Arkoma LLC | Tulsa, OK 74120-3017 | Oil & Gas Operator | Mar 2026 |
| 473 | Canyon Creek Energy Operating LLC | Tulsa, OK 74120 | Oil & Gas Operator | Mar 2026 |
| 474 | Canyon Creek Energy Texas, LLC | Tulsa, OK 74136 | Oil & Gas Operator | May 2017 |
| 475 | Canyon Creek Resources LLC | Tulsa, OK 74136 | Oil & Gas Operator | Jun 2026 |
| 476 | Canyon E & P Company | Dallas, TX 75206 | Oil Operator | Oct 2013 |
| 477 | Canyon Exploration Co. | Amarillo, TX 79105 | Oil & Gas Operator | Oct 2025 |
| 478 | Canyon Oil & Gas Exploration LLC | San Antonio, TX 78258 | Oil & Gas Operator | May 2002 |
| 479 | Canyon Operating LLC | Dallas, TX 75225 | Oil & Gas Operator | Jun 2026 |
| 480 | Canyon Operating Unit | San Angelo, TX 76904 | Oil & Gas Operator | Sep 1995 |
| 481 | Canyon Reef Brine LLC | Snyder, TX 79550 | Oil Operator | Jun 2026 |
| 482 | Canyon Ridge Energy LLC | Iowa Park, TX 76367 | Oil Operator | Nov 2024 |
| 483 | Cap Energy LLC | Greeley, CO 80634 | Oil & Gas Operator | Aug 2019 |
| 484 | Cap Oil Company | Ada, OK 74820 | Oil Operator | Feb 2026 |
| 485 | Cap Operating Inc. | Borger, TX 79008 | Oil & Gas Operator | Jun 2026 |
| 486 | Cap Production | | Oil Operator | Dec 2024 |
| 487 | Capataz Operating Inc | Midland, TX 79702 | Oil & Gas Operator | Sep 2020 |
| 488 | Capco Offshore Of Texas, Inc. | Houston, TX 77056 | Oil & Gas Operator | Jun 2026 |
| 489 | Capco Offshore, Inc. | Irving, TX 75063 | Oil & Gas Operator | May 2012 |
| 490 | Capco Resource Corporation | Orange,, CA 92869 | Oil Operator | Sep 2007 |
| 491 | Capco Resources Corporation | Irving, TX 75016 | Oil & Gas Operator | Mar 2004 |
| 492 | Capco Resources Of Texas, Inc | Irving, TX 75063 | Oil & Gas Operator | Jun 2003 |
| 493 | Cape Oil Associates | | Oil & Gas Operator | Sep 1997 |
| 494 | Cape Operating, Inc. | Longview, TX 75608 | Oil & Gas Operator | Nov 2007 |
| 495 | Cape, Randy | Tyler, TX 75703 | Oil & Gas Operator | Mar 2008 |
| 496 | Capio Oil & Gas, Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 2015 |
| 497 | Capital A Corp. | San Antonio, TX 78279 | Oil & Gas Operator | Jun 2002 |
| 498 | Capital Energy Group, Inc. | Bardonia, NY 10954 | Oil Operator | Jan 1998 |
| 499 | Capital Energy, LLC | Ripley, WV 25271 | Oil & Gas Operator | Dec 2021 |
| 500 | Capital Gas, Inc. | | Gas Operator | Jan 1998 |