| 401 | Mayfield Engineering Service | Tulsa, OK 74104 | Oil & Gas Operator | May 2025 |
| 402 | McGoldrick Oil Company | Shreveport, LA 71129 | Oil & Gas Operator | Jul 2020 |
| 403 | McNeill Randy & W R | Okmulgee, OK 74447 | Oil & Gas Operator | Nov 2013 |
| 404 | McQueen Ed & Company Inc | Lindsey, OK 73052 | Oil & Gas Operator | Apr 2014 |
| 405 | Mega Natural Gas Co | Tulsa, OK 74133 | Oil & Gas Operator | Jul 1996 |
| 406 | Metro Energy Group, Inc. | Bossier City, LA 71112 | Oil & Gas Operator | May 2013 |
| 407 | Meyerhoff & Cox Inc | Tulsa, OK 74135-7830 | Oil Operator | Aug 1993 |
| 408 | Mid-Con Energy Operating, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | May 2020 |
| 409 | Mid-Continent Energy Operating Company | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2025 |
| 410 | Midcontinent Oil & Gas Company | Phoenix, AZ 85022-6180 | Oil & Gas Operator | Jun 2012 |
| 411 | Mija LLC | Oklahoma City, OK 73151 | Oil & Gas Operator | Mar 2025 |
| 412 | Miller B Investments | Tulsa, OK 74170 | Oil & Gas Operator | Nov 2007 |
| 413 | Minihan Oil And Gas Company | Seminole, OK 74868-9790 | Oil & Gas Operator | Sep 2014 |
| 414 | Mitchell Cecil D | Haskell, OK 74436-7667 | Oil & Gas Operator | Apr 2020 |
| 415 | MJB Production Company, Inc. | Brownfield, TX 79316 | Oil & Gas Operator | May 2025 |
| 416 | Mode Oil & Gasdev LTD12/21/Ofb 9-98 | | Oil & Gas Operator | May 2013 |
| 417 | Monroe Natural Gas Inc | Norman, OK 73071 | Oil & Gas Operator | Feb 2025 |
| 418 | Montgomery Jake E | Henryetta, OK 74437 | Oil & Gas Operator | Jan 2025 |
| 419 | Montgomery Oil & Gas Expl Inc | Tulsa, OK 74170-1884 | Oil & Gas Operator | Mar 2005 |
| 420 | Moran-K Oil LLC | Seminole, OK 74868 | Oil & Gas Operator | Mar 2025 |
| 421 | Morgan Robert M / L Ladean | Wewoka, OK 74884 | Oil & Gas Operator | Jul 2015 |
| 422 | Mott Petroleum Corporation | Sugar Land, TX 77487 | Oil & Gas Operator | Aug 2024 |
| 423 | Nadel And Gussman, L.L.C. | Tulsa, OK 74119 | Oil & Gas Operator | May 2025 |
| 424 | Naifco Oil & Gas LLC | Oklahoma City, OK 73107 | Oil & Gas Operator | Feb 2025 |
| 425 | Natural Resources Operating LLC | Norman, OK 73071-1295 | Oil & Gas Operator | Jan 2023 |
| 426 | Nbi Services, Inc. | Tulsa, OK 74159 | Oil & Gas Operator | May 2025 |
| 427 | New Dominion LLC | Tulsa, OK 74119-3220 | Oil & Gas Operator | Feb 2025 |
| 428 | New Energy Corporation | Rancho Santa Fe, CA 92067-1990 | Oil & Gas Operator | Jul 2024 |
| 429 | New Era Gas Co Inc | Bull Shoals, AR 72619-0130 | Gas Operator | Mar 2004 |
| 430 | Nexus Resources Corporation | Drumright, OK 74030 | Oil & Gas Operator | Jan 2013 |
| 431 | Nijean, Inc. | Shawnee, OK 74802 | Oil & Gas Operator | Feb 2012 |
| 432 | Nixon Properties Inc | Tulsa, OK 74104 | Oil & Gas Operator | Aug 2023 |
| 433 | Noble Energy Inc | Midland, TX 79706 | Oil & Gas Operator | May 2025 |
| 434 | Noble Energy Production Inc | Houston, TX 77067 | Oil & Gas Operator | May 2025 |
| 435 | Northbrook Oil & Gas Company | Norman, OK 73070-4916 | Oil & Gas Operator | Jun 2016 |
| 436 | O'Brien Oil Corporation | Guthrie, OK 73044-3154 | Oil & Gas Operator | Feb 2025 |
| 437 | Oakland Petroleum Oper Co., Inc. | Kilgore, TX 75663 | Oil & Gas Operator | May 2025 |
| 438 | Oex-1 LLC | Tulsa, OK 74105-5153 | Oil & Gas Operator | Mar 2024 |
| 439 | Oil Creek Production Company | Prague, OK 74864-0667 | Oil & Gas Operator | Feb 2025 |
| 440 | Oil Production Systems Inc | Cushing, OK 74023 | Oil & Gas Operator | Jan 2013 |
| 441 | Okie Crude Company | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2025 |
| 442 | Oklahoma Gas & Oil Corp | | Oil Operator | Oct 2018 |
| 443 | Oklahoma Petroleum MGMT Corp | Tulsa, OK 74119 | Oil & Gas Operator | Jun 1993 |
| 444 | Okmar Oil Company | Marietta, OH 45750 | Oil & Gas Operator | Jun 2005 |
| 445 | Okt Petroleum Company Inc | Oklahoma City, OK 73118-7425 | Oil & Gas Operator | Oct 2013 |
| 446 | Oktex Operating LLC | Edmond, OK 73013-1961 | Oil & Gas Operator | May 2020 |
| 447 | Olympia Oil Inc | Edmond, OK 73083-7088 | Oil & Gas Operator | Jul 2020 |
| 448 | Orion Exploration LLC | Tulsa, OK 74105-5153 | Oil & Gas Operator | Apr 2015 |
| 449 | Orion Exploration Partners LLC | Tulsa, OK 74105-5153 | Oil & Gas Operator | Jan 2025 |
| 450 | Oscar'S Well Service Inc | Okemah, OK 74859 | Oil & Gas Operator | Apr 1998 |
| 451 | Oshtah Oil Company LLC | Stratford, OK 74872 | Oil & Gas Operator | Sep 2018 |
| 452 | Osterhout Phillip L | Drumright, OK 74030-0693 | Oil & Gas Operator | Jan 2014 |
| 453 | Ovintiv Mid-Continent Inc. | The Woodlands, TX 77380-2764 | Oil & Gas Operator | Mar 2025 |
| 454 | Oxley John C | Tulsa, OK 74103 | Oil & Gas Operator | Sep 1996 |
| 455 | Oxley Petroleum | Tulsa, OK 74119-3609 | Oil & Gas Operator | Jan 2020 |
| 456 | Oxley Petroleum Co | Oklahoma City, OK 73118-1044 | Oil & Gas Operator | Sep 2017 |
| 457 | P & C Oil Company | Leona, TX 75850 | Oil & Gas Operator | Mar 2025 |
| 458 | P-2 Exploraton Co Inc | Pampa, TX 79065-2920 | Oil & Gas Operator | Jun 1996 |
| 459 | Pace Exploration LLC | Tulsa, OK 74133 | Oil & Gas Operator | Feb 2025 |
| 460 | Pacific Enterprise Oil Co USA | Los Angeles, CA 90071-2005 | Oil & Gas Operator | Aug 2012 |
| 461 | Pak Energy LLC | Calgary, AB T3A-5E8 | Oil Operator | Sep 2022 |
| 462 | Palm Operating LLC | Oklahoma City, OK 73106-5646 | Oil & Gas Operator | Nov 2019 |
| 463 | Paluca Petroleum Inc | Holdenville, OK 74848 | Oil & Gas Operator | Mar 2025 |
| 464 | Pan Western Energy Corporation | Tulsa, OK 74114 | Oil & Gas Operator | May 2025 |
| 465 | Panada Exploration, Inc. | Tulsa, OK 74135 | Oil & Gas Operator | Jun 1996 |
| 466 | Par Oil Company Inc | Denver, CO 80201 | Oil & Gas Operator | Jun 2003 |
| 467 | Parish Petroleum Company | Tulsa, OK 74137 | Oil & Gas Operator | Feb 2025 |
| 468 | Parker & Parsley Dev Co | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 469 | Parks Bill M | Seminole, OK 74818-1648 | Oil & Gas Operator | Apr 2014 |
| 470 | Patco Investments Inc | Seminole, OK 74868 | Oil Operator | Nov 2007 |
| 471 | Patina Oil & Gas Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2016 |
| 472 | Patina Oklahoma Corp | Duncan, OK 73533-9523 | Oil & Gas Operator | Nov 2014 |
| 473 | Payneco Pipeline Company | Yale, OK 74085 | Oil & Gas Operator | Dec 2000 |
| 474 | Pearl Petroleum Inc | Lawton, OK 73501-5821 | Oil & Gas Operator | Jan 2014 |
| 475 | Pelto Oil Co | Houston, TX 77002 | Oil & Gas Operator | Nov 1998 |
| 476 | Pemex Inc | Dallas, TX 75367-0249 | Oil & Gas Operator | Nov 2015 |
| 477 | Petro Davis Inc | Oklahoma City, OK 73142-1807 | Oil & Gas Operator | Jan 2013 |
| 478 | Petro Warrior LLC | Wichita, KS 67206 | Oil & Gas Operator | Feb 2025 |
| 479 | Petro-Chase Energy Corp | Oklahoma City, OK 73135-6205 | Oil & Gas Operator | Jan 2007 |
| 480 | Petro-Mac Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2025 |
| 481 | Petroflow Energy Corporation | Tulsa, OK 74119-5405 | Oil & Gas Operator | Oct 2016 |
| 482 | Petroleum Explo Prod Inc | Oilton, OK 74052 | Oil & Gas Operator | Jan 2017 |
| 483 | Petroleum Inc | Wichita, KS 67202 | Oil & Gas Operator | Oct 2021 |
| 484 | Petroleum Management Prof Inc | Oklahoma City, OK 73120-1848 | Oil & Gas Operator | Apr 2009 |
| 485 | Petroleum Management, Inc. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | May 2025 |
| 486 | Petromark Resources Company | Tulsa, OK 74136 | Oil & Gas Operator | Sep 1993 |
| 487 | Petron Energy Inc | Dallas, TX 75252 | Oil & Gas Operator | May 2025 |
| 488 | Phase III Drilling Inc | Wetumka, OK 74883-0333 | Oil & Gas Operator | Feb 2025 |
| 489 | Phillips Oil Operating Co | Enid, OK 73703-4921 | Oil & Gas Operator | May 2019 |
| 490 | Pinnacle Corporation (The) | Broken Arrow, OK 74012 | Oil & Gas Operator | Nov 2014 |
| 491 | Pinnacle Exploration Inc | Edmond, OK 73003 | Oil & Gas Operator | Mar 2024 |
| 492 | Pittencrieff America Inc | Abilene, TX 79608 | Oil & Gas Operator | Feb 2003 |
| 493 | Pollard Jr G W | Okmulgee, OK 74447 | Oil & Gas Operator | Apr 2015 |
| 494 | Ponder Oil Producers LLC | Okemah, OK 74859 | Oil & Gas Operator | Nov 2024 |
| 495 | Pope Charles Edward | Morris, OK 74445 | Oil & Gas Operator | Mar 2023 |
| 496 | Porter Oil And Gas Inc | Fort Smith, AR 72903-6906 | Oil & Gas Operator | Feb 2025 |
| 497 | Portfolio Oil Corporation | Oklahoma City, OK 73119 | Oil & Gas Operator | May 2013 |
| 498 | Pound Robert M | Bristow, OK 74010 | Oil & Gas Operator | Sep 2014 |
| 499 | Powell Jess L | Sapulpa, OK 74066 | Oil & Gas Operator | Dec 2024 |
| 500 | Prentice Ed | Allen, OK 74825 | Oil & Gas Operator | Feb 2025 |