| 401 | Combined Resources Corporation | Edmond, OK 73083 | Oil & Gas Operator | Sep 2026 |
| 402 | Comdisco Resources Inc | | Oil Operator | Aug 2004 |
| 403 | Comet Oil Company | Velma, OK 73091 | Oil & Gas Operator | May 2005 |
| 404 | Comet-Haines Oil Company | Sulphur, OK 73086-0546 | Oil & Gas Operator | Mar 2013 |
| 405 | Command Energy Operating LLC | Tulsa, OK 74119 | Oil & Gas Operator | Jun 2026 |
| 406 | Compadre Drilling & Expl Corp | Ardmore, OK 73402 | Oil & Gas Operator | Mar 2015 |
| 407 | Compass Drilling Inc | Enid, OK 73702-5467 | Oil & Gas Operator | Sep 2014 |
| 408 | Compass Resources | Enid, OK 73702 | Oil & Gas Operator | Dec 2007 |
| 409 | Complete Energy Services LLC | Gainesville, TX 76240 | Oil Operator | Aug 2022 |
| 410 | Comstock Oil & Gas, LP | Frisco, TX 75034 | Oil & Gas Operator | Aug 2019 |
| 411 | Concho Exploration Inc | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2015 |
| 412 | Concord Energy, Inc. | Glen Rose, TX 76043 | Oil & Gas Operator | Sep 2026 |
| 413 | Concorde Resources Corporation | Eufaula, OK 74432 | Oil & Gas Operator | Jan 2026 |
| 414 | Condrin Oil 1985-A LTD | Tulsa, OK 74136 | Oil & Gas Operator | Nov 1998 |
| 415 | Confed Oil Incorporated | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2008 |
| 416 | Confederate Bay LLC | Okemah, OK 74859 | Oil & Gas Operator | Jun 2026 |
| 417 | Confederate Spooling Inc | Okemah, OK 74859-2409 | Oil & Gas Operator | Apr 2020 |
| 418 | Conklin Robert L Dba Conklin Oil LLC | Tulsa, OK 74153 | Oil Operator | May 2026 |
| 419 | Conley, John | | Oil Operator | Aug 2000 |
| 420 | Conn-Okla Producing Co Inc | | Oil & Gas Operator | Nov 1992 |
| 421 | Conner Family Limited Partnership | Humble, TX 77338 | Oil & Gas Operator | Apr 2026 |
| 422 | Conner Jelly | Seminole, OK 74868 | Oil & Gas Operator | Mar 1996 |
| 423 | Conner Production Co LLC | Seminole, OK 74868 | Oil & Gas Operator | May 2026 |
| 424 | Conoco Inc | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 425 | ConocoPhillips Company | Midland, TX 79701 | Oil & Gas Operator | Sep 2026 |
| 426 | Consolidated Exploration Company | Nichols Hill, OK 73116 | Oil & Gas Operator | Apr 2015 |
| 427 | Consolidated Oil & Gas Inc | Wichita, KS 67202 | Oil & Gas Operator | Dec 2012 |
| 428 | Consolidated Peto Equity LTD | La Crescenta, CA 91214 | Oil & Gas Operator | Dec 1996 |
| 429 | Consolidated Production Inc. | Seminole, OK 74868 | Oil & Gas Operator | May 2026 |
| 430 | Consolidated Properties | Tulsa, OK 74129 | Oil & Gas Operator | Jan 2017 |
| 431 | Consolidated Resources Corp | Shawnee, OK 74801 | Oil & Gas Operator | Sep 2014 |
| 432 | Contango Midstream Company | Houston, TX 77002-3023 | Oil & Gas Operator | Jun 2026 |
| 433 | Contango Resources LLC | Andrews, TX 79714 | Oil & Gas Operator | Jun 2026 |
| 434 | Continental Energy | Garden City, KS 67846-0918 | Oil & Gas Operator | Jul 2017 |
| 435 | Continental Energy Operating LLC | Tulsa, OK 74114-1302 | Oil & Gas Operator | Jun 2026 |
| 436 | Continental Exploration LLC | Richardson, TX 75080 | Oil & Gas Operator | Sep 2026 |
| 437 | Continental Gas Inc | Enid, OK 73702-5103 | Oil & Gas Operator | Apr 2012 |
| 438 | Continental Oil & Refining Co | Catoosa, OK 74015-0831 | Oil & Gas Operator | Feb 2026 |
| 439 | Continental Operating Co. | Houston, TX 77024 | Oil & Gas Operator | Sep 2026 |
| 440 | Continental Resources, Inc. | Oklahoma City, OK 73126 | Oil & Gas Operator | Sep 2026 |
| 441 | Contreras Al Consultants Inc | Oklahoma City, OK 73113-0762 | Oil & Gas Operator | Oct 2020 |
| 442 | Convest Energy Corporation | Houston, TX 77057 | Oil & Gas Operator | Sep 2014 |
| 443 | Cook L D | Bartlesville, OK 74005-2306 | Oil & Gas Operator | Nov 2005 |
| 444 | Cook Oil Company | Wewoka, OK 74884 | Oil & Gas Operator | May 2026 |
| 445 | Cook Robert L | Rockwall, TX 75087-0892 | Oil & Gas Operator | Mar 2015 |
| 446 | Cook W R Inc | Duncan, OK 73534-0069 | Oil & Gas Operator | Jun 2000 |
| 447 | Cook William Glenn | Wewoka, OK 74884-0727 | Oil & Gas Operator | Nov 2000 |
| 448 | Cooke County Production Company | Shawnee, OK 74801-1800 | Oil & Gas Operator | Jan 2022 |
| 449 | Coon Creek Gas Inc | | Oil & Gas Operator | Mar 2014 |
| 450 | Cooper A L & Mae C | | Oil & Gas Operator | Jan 2001 |
| 451 | Cooper Energy Corp | | Oil & Gas Operator | Jun 1995 |
| 452 | Cooper John T | Duncan, OK 73534 | Oil & Gas Operator | Sep 2014 |
| 453 | Cooper Lisa L | Cushing, OK 74023 | Oil & Gas Operator | Mar 2015 |
| 454 | Cooper Mineral Group Inc | Bellaire, TX 77401 | Oil & Gas Operator | Feb 2004 |
| 455 | Cooper Oil Inc | Duncan, OK 73534 | Oil & Gas Operator | Sep 2014 |
| 456 | Cooper Operating LLC | Oklahoma City, OK 73134 | Oil & Gas Operator | Jun 2026 |
| 457 | Cooper Production Company | New Braunfels, TX 78132 | Oil & Gas Operator | Sep 2021 |
| 458 | Coppock Herb Energy | Fairview, OK 73737-1037 | Oil & Gas Operator | May 2018 |
| 459 | Coquina Oil Corporation | Houston, TX 77227 | Oil & Gas Operator | Mar 2015 |
| 460 | Coral Production Corporation | Denver, CO 80201 | Oil & Gas Operator | Apr 2026 |
| 461 | Corbell Wayne L | Arlinton, TX 76006 | Oil & Gas Operator | Apr 2023 |
| 462 | Cordillera Energy Partners II LLC | Greenwood VIllage, CO 80111-2856 | Oil & Gas Operator | May 2026 |
| 463 | Cordillera Energy Partners III LLC | Greenwood VIllage, CO 80111-2856 | Oil & Gas Operator | Mar 2014 |
| 464 | Cordillera Energy Partners, LLC | Greenwood VLG, CO 80111 | Oil & Gas Operator | Mar 2020 |
| 465 | Corlena Oil Company | Amarillo, TX 79101 | Oil & Gas Operator | Sep 2026 |
| 466 | Corley G R | | Oil & Gas Operator | Jun 2009 |
| 467 | Corley Production Company | Wilson, OK 73463-7218 | Oil Operator | Jun 2026 |
| 468 | Corley Production Inc | Comanche, OK 73529-4668 | Oil Operator | Mar 2015 |
| 469 | Corman, Jack | Dallas, TX 75231 | Oil & Gas Operator | May 2022 |
| 470 | Cornelius Dale | Willow, OK 73673 | Oil Operator | Apr 2026 |
| 471 | Cornelius Oil Company | Kellyville, OK 74039-0459 | Oil & Gas Operator | Jul 2015 |
| 472 | Cornelius Oil Inc | Kellyville, OK 74039 | Oil & Gas Operator | May 2026 |
| 473 | Cornelius Petroleum Inc | | Oil & Gas Operator | May 2026 |
| 474 | Cornelius Phillip J & Connie | Kellyville, OK 74039 | Oil & Gas Operator | Dec 2000 |
| 475 | Cornelius Tony | Sapulpa, OK 74066-5845 | Oil & Gas Operator | May 2026 |
| 476 | Cornelius, Steven L | | Oil Operator | Sep 2015 |
| 477 | Cornell Glen R | Pauls Valley, OK 73075-9606 | Oil & Gas Operator | Oct 2013 |
| 478 | Corner Energy LLC | Oklahoma City, OK 73156-0548 | Oil & Gas Operator | Mar 2015 |
| 479 | Cornerstone E & P Company LP | Irving, TX 75038 | Oil & Gas Operator | Nov 2010 |
| 480 | Coronado Energy Partners LLC | Tulsa, OK 74136 | Oil & Gas Operator | May 2026 |
| 481 | Coronado Great Plains LLC | Tulsa, OK 74137-2832 | Gas Operator | Apr 2013 |
| 482 | Coronado Oklahoma LLC | Tulsa, OK 74133-7036 | Gas Operator | Apr 2020 |
| 483 | Coronado Petroleum Corporation | Oklahoma City, OK 73102-4803 | Oil & Gas Operator | May 2026 |
| 484 | Corpening, Joe F. | Bowie, TX 76230 | Oil & Gas Operator | Oct 2013 |
| 485 | Corterra Energy Operating LLC | Tulsa, OK 74119-4844 | Oil & Gas Operator | Aug 2021 |
| 486 | Cortez Operating Company | Fort Worth, TX 76102 | Oil & Gas Operator | Nov 2016 |
| 487 | Corwin B V | Enid, OK 73701 | Oil & Gas Operator | Apr 2017 |
| 488 | Cory, Kenneth W. | Bellaire, TX 77401 | Oil & Gas Operator | Mar 2012 |
| 489 | Costilla Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 490 | Costilla Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 491 | Coterra Energy Operating Co. | Midland, TX 79706 | Oil & Gas Operator | Sep 2026 |
| 492 | Cotton County Ventures | Estes Park, CO 80517 | Oil Operator | Nov 2003 |
| 493 | Cotton Petroleum Corporation | Tulsa, OK 74102 | Oil & Gas Operator | Jan 2005 |
| 494 | Cottonmouth SWD LLC | Tulsa, OK 74103-3522 | Oil Operator | Jun 2026 |
| 495 | Couch Donald W | Marlow, OK 73055 | Oil & Gas Operator | May 2026 |
| 496 | Couch Fred J | Broken Arrow, OK 74012 | Oil Operator | Mar 2010 |
| 497 | Cougar Energy Investment LLC | Spring, TX 77387-7277 | Oil & Gas Operator | Sep 2014 |
| 498 | Cougar Oil | | Oil Operator | May 2026 |
| 499 | Coughlin, Daniel L | | Oil Operator | Aug 2000 |
| 500 | Council Oak Resources LLC | Tulsa, OK 74103-3500 | Oil & Gas Operator | May 2026 |