| 401 | McCoy Petroleum Corporation | Wichita, KS 67207 | Oil & Gas Operator | Feb 2026 |
| 402 | McMillin C C & Company Inc | Guthrie, OK 73044 | Oil & Gas Operator | Jan 2026 |
| 403 | McNeal Production Inc | Perry, OK 73077-0268 | Oil & Gas Operator | Nov 2014 |
| 404 | McRae & Henry LTD | Golden, CO 80401 | Oil & Gas Operator | May 2022 |
| 405 | Meadowbrook Oil Corporation Of Ok Inc | Del City, OK 73115-3608 | Oil & Gas Operator | Feb 2026 |
| 406 | Medicine Bow Operating Company | Houston, TX 77002 | Oil & Gas Operator | Apr 2014 |
| 407 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Apr 2026 |
| 408 | Mesa Operating LP | Irving, TX 75039-3746 | Oil & Gas Operator | Oct 2010 |
| 409 | Mid Center Oil Company | | Oil & Gas Operator | Mar 2014 |
| 410 | Mid-Con Energy Operating, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Feb 2026 |
| 411 | Mid-Continent Energy Operating Company | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2026 |
| 412 | Middle Bay Production Co. Inc. | Houston, TX 77010 | Oil & Gas Operator | Sep 2014 |
| 413 | Midnight Hour LLC | Enid, OK 73702 | Oil & Gas Operator | Apr 2020 |
| 414 | Midstates Oil Company | Oklahoma City, OK 73112 | Oil & Gas Operator | Nov 2000 |
| 415 | Moabb Oil Corp | | Oil & Gas Operator | Apr 1998 |
| 416 | Montego Resources Inc | Oklahoma City, OK 73172-0192 | Oil & Gas Operator | Mar 2015 |
| 417 | Monty L Hott Production Corporation | Oklahoma City, OK 73142 | Oil & Gas Operator | Jan 2026 |
| 418 | Moore Clay | Bradenton, FL 34211 | Oil & Gas Operator | Jan 2026 |
| 419 | Moore Richard L | Morris, OK 74445 | Oil Operator | Aug 2013 |
| 420 | Moran-K Oil LLC | Seminole, OK 74868 | Oil & Gas Operator | Feb 2026 |
| 421 | Morris Pete Drilling Company | | Oil Operator | Feb 1999 |
| 422 | MT Dora Energy Corporation | Duncan, OK 73533-1829 | Oil & Gas Operator | Apr 2014 |
| 423 | MT Dora Energy LLC | Houston, OK 77056-1940 | Oil & Gas Operator | Jun 2019 |
| 424 | MT Energy LLC | Waskom, TX 75692 | Oil & Gas Operator | Apr 2026 |
| 425 | Mud Operations Inc | Ames, OK 73718-9501 | Oil & Gas Operator | Feb 2026 |
| 426 | Mullen William Company | Edmond, OK 73083-1372 | Oil & Gas Operator | May 1999 |
| 427 | Mustang Fuel Corporation | Oklahoma City, OK 73114 | Oil & Gas Operator | Apr 2026 |
| 428 | Mustang Gas Products LLC | Oklahoma City, OK 73114-7406 | Oil & Gas Operator | Sep 2022 |
| 429 | Nadel And Gussman LLC | Tulsa, OK 74119 | Oil & Gas Operator | Apr 2026 |
| 430 | Naifco Oil & Gas LLC | Oklahoma City, OK 73107 | Oil & Gas Operator | Jan 2026 |
| 431 | National Energy Group Inc | Dallas, TX 75206 | Oil & Gas Operator | Sep 2014 |
| 432 | Nbi Services, Inc. | Tulsa, OK 74159 | Oil & Gas Operator | Apr 2026 |
| 433 | New Dominion LLC | Tulsa, OK 74119-3220 | Oil & Gas Operator | Feb 2026 |
| 434 | NFC Petroleum Corporation | Tulsa, OK 74121 | Oil & Gas Operator | Jun 1996 |
| 435 | Nielson & Associates, Inc | Cody, WY 82414 | Oil & Gas Operator | Feb 2016 |
| 436 | Noble Energy Inc | Midland, TX 79706 | Oil & Gas Operator | Apr 2026 |
| 437 | Noble Energy Production Inc | Houston, TX 77067 | Oil & Gas Operator | Apr 2026 |
| 438 | Noble Operating Company Inc | Garden City, KS 67846 | Oil & Gas Operator | Sep 2014 |
| 439 | Nogp Operating Company Inc | Tomball, TX 77377 | Oil & Gas Operator | Jan 2026 |
| 440 | North American Operating, LLC | Ardmore, OK 73401 | Oil & Gas Operator | Feb 2026 |
| 441 | Oil Production Systems Inc | Cushing, OK 74023 | Oil & Gas Operator | Jan 2013 |
| 442 | Oil Ventures LTD | | Oil & Gas Operator | Jan 2013 |
| 443 | Okie Crude Company | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2026 |
| 444 | Oklahoma Equipment & Salvage | Oklahoma City, OK 73120-5903 | Oil & Gas Operator | Mar 2015 |
| 445 | Oklahoma Oil & Gas MGMT Inc | Edmond, OK 73083-6786 | Oil & Gas Operator | Jan 2026 |
| 446 | Oklahoma Oil Tactics Inc | Edmond, OK 73003-1351 | Oil & Gas Operator | Mar 2015 |
| 447 | Okmar Oil Company | Marietta, OH 45750 | Oil & Gas Operator | Jun 2005 |
| 448 | Oktex Operating LLC | Edmond, OK 73013-1961 | Oil & Gas Operator | May 2020 |
| 449 | Olympic Petroleum Co | Tulsa, OK 74114 | Oil & Gas Operator | Jun 1998 |
| 450 | Oneok Field Services Company | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2026 |
| 451 | Onyx Energy Corporation | Oklahoma City, OK 73157 | Oil & Gas Operator | May 1994 |
| 452 | Onyx Properties Corp | Oklahoma City, OK 73114 | Oil & Gas Operator | May 2006 |
| 453 | Otc/Occ Not Assigned | | Oil & Gas Operator | Dec 2024 |
| 454 | Pablo Energy II, LLC | Amarillo, TX 79105 | Oil & Gas Operator | Jan 2026 |
| 455 | Pactola Development Co | Tulsa, OK 74159 | Oil & Gas Operator | Sep 2004 |
| 456 | Pal Kids Inc | Coronado, CA 92118 | Oil & Gas Operator | Nov 2000 |
| 457 | Palm Oil & Gas Company | Sedona, AZ 86340 | Oil & Gas Operator | Feb 2026 |
| 458 | Pan Western Energy Corporation | Tulsa, OK 74114 | Oil & Gas Operator | Apr 2026 |
| 459 | Panenergy Services Inc | Houston, TX 77525 | Oil & Gas Operator | May 2001 |
| 460 | Pangaea Exploration Corp | Edmond, OK 73013 | Oil & Gas Operator | May 2019 |
| 461 | Paradigm Twenty LLC | Stillwater, OK 74074-1745 | Oil & Gas Operator | Jan 2026 |
| 462 | Parker & Parsley Dev Co | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 463 | Parkway Petroleum, Inc. | Giddings, TX 78942 | Oil & Gas Operator | Jul 1997 |
| 464 | Patina Oil & Gas Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2016 |
| 465 | Patina Oklahoma Corp | Duncan, OK 73533-9523 | Oil & Gas Operator | Nov 2014 |
| 466 | Patterson Eddy L | Tulsa, OK 74133 | Oil & Gas Operator | Feb 2022 |
| 467 | PBT Enterprises Inc | Garber, OK 73738 | Oil & Gas Operator | Jun 2023 |
| 468 | Pearl Petroleum Inc | Lawton, OK 73501-5821 | Oil & Gas Operator | Jan 2014 |
| 469 | Pedestal Oil Company Inc | Oklahoma City, OK 73101-1522 | Oil & Gas Operator | May 2019 |
| 470 | Pegasus Energy Corporation | Oklahoma City, OK 73162 | Oil & Gas Operator | Mar 2015 |
| 471 | Penn Production Company Inc | | Oil & Gas Operator | Nov 2014 |
| 472 | Penn VIrginia MC Operating Co LLC | Houston, TX 77084-7213 | Oil & Gas Operator | Sep 2025 |
| 473 | Pepin Oil Co | Stillwater, OK 74076 | Oil & Gas Operator | Oct 2013 |
| 474 | Pepin Operating Company Inc | Stillwater, OK 74075-9535 | Oil & Gas Operator | May 2009 |
| 475 | Performance Petroleum Company LLC | Barnsdall, OK 74002 | Oil & Gas Operator | Feb 2026 |
| 476 | Perry Production Company Inc | Perry, OK 73077-0412 | Oil & Gas Operator | May 2006 |
| 477 | Petro Speed Inc | Norman, OK 73069-8116 | Oil & Gas Operator | Mar 2015 |
| 478 | Petro-Management Assoc., Inc. | Edmond, OK 73083-2346 | Oil & Gas Operator | Jun 2007 |
| 479 | Petroleum Management Prof Inc | Oklahoma City, OK 73120-1848 | Oil & Gas Operator | Apr 2009 |
| 480 | Petroleum Management, Inc. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Apr 2026 |
| 481 | Petroleum Reserve Corporation | Plymouth MTNG, PA 19462 | Oil & Gas Operator | May 2008 |
| 482 | Petroleum Resources Co | Wichita, KS 67206 | Oil & Gas Operator | May 2000 |
| 483 | Phillips Oil Operating Co | Enid, OK 73703-4921 | Oil & Gas Operator | May 2019 |
| 484 | Pinnacle Corporation (The) | Broken Arrow, OK 74012 | Oil & Gas Operator | Nov 2014 |
| 485 | Pioneer Resources Prod LP | Irving, TX 75039-3745 | Oil & Gas Operator | Feb 2005 |
| 486 | Plainsmen Energy LLC | Enid, OK 73703-5747 | Oil & Gas Operator | Feb 2026 |
| 487 | Pollok Energy LLC | Tulsa, OK 74159 | Oil & Gas Operator | Feb 2026 |
| 488 | Polo Operating Inc | Oklahoma City, OK 73112 | Oil & Gas Operator | May 2006 |
| 489 | Porter John B | Ketchum, OK 74349-0207 | Oil & Gas Operator | May 2000 |
| 490 | Porter John E "Gene" | Cushing, OK 74023 | Oil & Gas Operator | Aug 2000 |
| 491 | Post Oak Oil Company | Oklahoma City, OK 73112 | Oil & Gas Operator | Jul 2013 |
| 492 | Prime Energy Corp | Charleston, WV 25301-1707 | Oil & Gas Operator | Sep 2015 |
| 493 | Prime Operating Company | Midland, TX 79705 | Oil & Gas Operator | Apr 2026 |
| 494 | Primexx Operating Corporation | Dallas, TX 75206 | Oil & Gas Operator | Mar 2024 |
| 495 | Producers Oil Company | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2007 |
| 496 | Psa Inc | Chandler, OK 74834-4222 | Oil & Gas Operator | Jan 2026 |
| 497 | Pullers Oil Company LLC | Blackwell, OK 74631-9512 | Oil & Gas Operator | Jan 2026 |
| 498 | Quad J Oil & Gas LLC | Crescent, OK 73028 | Oil & Gas Operator | Feb 2026 |
| 499 | Quick Draw Tank Trucks Inc | Lamont, OK 74643-0158 | Oil Operator | Oct 1997 |
| 500 | R & B Trucking | Crescent, OK 73028-0775 | Oil & Gas Operator | Nov 2021 |