| 501 | Magnum Energy Inc | Norman, OK 73072-2403 | Oil & Gas Operator | Feb 2024 |
| 502 | Mallard Oil & Gas | Cody, WY 82414-9640 | Oil & Gas Operator | Oct 2019 |
| 503 | Malson Oil Company | Crawford, OK 73638 | Oil & Gas Operator | Dec 2016 |
| 504 | Maple Properties Corp | Dallas, TX 75204 | Oil & Gas Operator | Jan 1999 |
| 505 | Marathon Oil Company | Houston, TX 77024 | Oil & Gas Operator | Feb 2024 |
| 506 | Marjo Operating Company Inc | Tulsa, OK 741010729 | Oil & Gas Operator | Jan 2024 |
| 507 | Marjo Operating Mid-Continent LLC | | Oil & Gas Operator | Feb 2024 |
| 508 | Mark Holloway Inc | Oklahoma City, OK 73107-6526 | Oil & Gas Operator | Jan 2024 |
| 509 | Marlin Oil Corporation | Oklahoma City, OK 73113 | Oil & Gas Operator | Jan 2024 |
| 510 | Marshall Oil Corporation | Oklahoma City, OK 73154 | Oil & Gas Operator | Apr 2017 |
| 511 | Maverick Brothers Resources LLC | Enid, OK 73702-0392 | Oil & Gas Operator | Jan 2024 |
| 512 | Maxey Homer G | | Oil & Gas Operator | Nov 1997 |
| 513 | Maxim Energy Corporation | Baytown, TX 77520 | Oil & Gas Operator | Jan 2024 |
| 514 | May Petroleum, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Nov 1998 |
| 515 | McCord Al Inc | Norman, OK 73072-6720 | Oil & Gas Operator | Feb 2011 |
| 516 | McCullough G W | Norman, OK 73072 | Oil & Gas Operator | Aug 2000 |
| 517 | McGee, Tom Corporation | Booker, TX 79005 | Oil & Gas Operator | Jan 2024 |
| 518 | McNic Oil & Gas Midcontinent | Oklahoma City, OK 73154-0526 | Oil & Gas Operator | Jan 2024 |
| 519 | McQueen Ed & Company Inc | Lindsey, OK 73052 | Oil & Gas Operator | Apr 2014 |
| 520 | McRae & Henry LTD | Golden, CO 80401 | Oil & Gas Operator | May 2022 |
| 521 | Meade Energy Corporation | Oklahoma City, OK 73118-4015 | Oil & Gas Operator | Feb 2024 |
| 522 | Meadowbrook Oil Corporation Of Ok Inc | Del City, OK 73115-3608 | Oil & Gas Operator | Feb 2024 |
| 523 | Medallion Petroleum, Inc. | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2015 |
| 524 | Mendell Petroleum Corporation | Castle Rock, CO 80104-9045 | Oil & Gas Operator | Sep 2004 |
| 525 | Mep Operating LLC | | Oil & Gas Operator | Jan 2024 |
| 526 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Apr 2024 |
| 527 | Mesa Operating LP | Irving, TX 75039-3746 | Oil & Gas Operator | Oct 2010 |
| 528 | Metropolitan Resources Corp | Tulsa, OK 74169-1734 | Oil & Gas Operator | Mar 2015 |
| 529 | MGF Oil Corporation | Tulsa, OK 74121 | Oil & Gas Operator | Jun 1998 |
| 530 | Mid-Con Central Expl Co | Tulsa, OK 74136 | Oil & Gas Operator | Aug 2014 |
| 531 | Mid-Con Energy Operating, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | May 2020 |
| 532 | Mid-Con Energy Operating, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Feb 2024 |
| 533 | Midnight Hour LLC | Enid, OK 73702 | Oil & Gas Operator | Apr 2020 |
| 534 | Midwest Energy Corporation | Tulsa, OK 74105-6083 | Oil & Gas Operator | Aug 2016 |
| 535 | Mija LLC | | Oil & Gas Operator | Feb 2024 |
| 536 | Milmac Operating Company | Lubbock, TX 79408-2976 | Oil & Gas Operator | Sep 2004 |
| 537 | Mito Resources LLC | Edmond, OK 73013 | Oil & Gas Operator | Feb 2024 |
| 538 | Miura Petroleum, Inc. | Topeka, KS 66603 | Oil & Gas Operator | May 2006 |
| 539 | MJM Oil & Gas, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Aug 2003 |
| 540 | MJM Resources Inc | Norman, OK 73070-8777 | Oil & Gas Operator | Feb 2024 |
| 541 | Mobil Exp & Prod Us Inc | Houston, TX 77060-1991 | Oil & Gas Operator | May 2001 |
| 542 | Monarch Petroleum Corporation | FT Worth, TX 76102 | Oil & Gas Operator | Dec 2019 |
| 543 | Monroe Natural Gas Inc | Norman, OK 73070-5687 | Oil & Gas Operator | Jan 2024 |
| 544 | Monty L Hott Production Corporation | Oklahoma City, OK 73142 | Oil & Gas Operator | Jan 2024 |
| 545 | Moore & Moore Energy Inc | Purcell, OK 73080-0674 | Oil & Gas Operator | Dec 2012 |
| 546 | Moore Richard L | Morris, OK 74445 | Oil Operator | Aug 2013 |
| 547 | Mud Operations Inc | Ames, OK 73718-9501 | Oil & Gas Operator | Feb 2024 |
| 548 | Mustang Fuel Corp. Of Oklahoma | Oklahoma City, OK 73106 | Oil & Gas Operator | Nov 2016 |
| 549 | Mustang Fuel Corporation | Oklahoma City, OK 73114 | Oil & Gas Operator | Feb 2024 |
| 550 | Mustang Gas Products LLC | Oklahoma City, OK 73114-7406 | Oil & Gas Operator | Sep 2022 |
| 551 | MW Petroleum Corporation | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |
| 552 | Nadel And Gussman, L.L.C. | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2024 |
| 553 | National Energy Group Inc | Dallas, TX 75206 | Oil & Gas Operator | Sep 2014 |
| 554 | Native Exploration Operating LLC | | Oil & Gas Operator | Jan 2024 |
| 555 | Nbi Services, Inc. | Tulsa, OK 74159 | Oil & Gas Operator | Apr 2024 |
| 556 | Neg Operating LLC | Oklahoma City, OK 73101 | Oil & Gas Operator | Apr 2017 |
| 557 | Nelson Exploration Corporation | | Oil & Gas Operator | Jan 2024 |
| 558 | Nemaha Environmental Services LLC | Enid, OK 73703 | Oil Operator | Feb 2024 |
| 559 | New Dominion LLC | Tulsa, OK 74119-3220 | Oil & Gas Operator | Jan 2024 |
| 560 | NFC Petroleum Corporation | Tulsa, OK 74121 | Oil & Gas Operator | Jun 1996 |
| 561 | Nielson & Associates Inc | Cody, WY 82414 | Oil & Gas Operator | Feb 2016 |
| 562 | Nordstrand Engineering Inc | Houston, TX 77019 | Oil & Gas Operator | Apr 2024 |
| 563 | North American Royalties, Inc. | Chattanooga, TN 37408 | Oil & Gas Operator | Oct 2001 |
| 564 | Nova Energy Corporation | Denver, CO 80201 | Oil & Gas Operator | Jun 2003 |
| 565 | Nytex, L.L.C. | Edmond, OK 73083 | Oil & Gas Operator | Feb 2006 |
| 566 | O G & E | Oklahoma City, OK 73124-0300 | Oil & Gas Operator | Feb 2014 |
| 567 | O K Swabbing Inc | Hennessey, OK 73742-0835 | Oil & Gas Operator | Jan 2024 |
| 568 | Oak Tree Natural Res LLC | Oklahoma City, OK 73120-5065 | Oil & Gas Operator | Mar 2015 |
| 569 | Oklahoma & Northwestern Co. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jan 1997 |
| 570 | Oklahoma Equipment & Salvage | Oklahoma City, OK 73120-5903 | Oil & Gas Operator | Mar 2015 |
| 571 | Oklahoma Liquid Resources Inc | Owasso, OK 74055-0841 | Oil & Gas Operator | Jan 2024 |
| 572 | Oklahoma Oil & Gas MGMT Inc | | Oil & Gas Operator | Jan 2024 |
| 573 | Oklahoma Oil Tactics Inc | Edmond, OK 73003-1351 | Oil & Gas Operator | Mar 2015 |
| 574 | Oklahoma Petroleum Allies LLC | Ardmore, OK 73401 | Oil Operator | Oct 2023 |
| 575 | Oklahoma Rig & Salvage, Inc. | Oklahoma City, OK 73114 | Oil & Gas Operator | Mar 2015 |
| 576 | Okland Oil Company | Oklahoma City, OK 73102-9022 | Oil & Gas Operator | Feb 2024 |
| 577 | Old Dominion Oil Corporation | Oklahoma City, OK 73107 | Oil & Gas Operator | Apr 2009 |
| 578 | Omni Oil & Gas, Inc. | San Antonio, TX 78229 | Oil & Gas Operator | Oct 2017 |
| 579 | Oneok Exploration Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 580 | Oneok Field Services Company | Tulsa, OK 74103 | Oil & Gas Operator | Jul 2022 |
| 581 | Oneok Gas Transportation Co | Tulsa, OK 74121-2089 | Oil & Gas Operator | Oct 2014 |
| 582 | Oneok Resources Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 583 | Onyx Energy Corporation | Oklahoma City, OK 73157 | Oil & Gas Operator | May 1994 |
| 584 | Onyx Properties Corp | Oklahoma City, OK 73114 | Oil & Gas Operator | May 2006 |
| 585 | Otc Petroleum Corporation | Oklahoma City, OK 73116 | Oil & Gas Operator | Mar 2015 |
| 586 | Outback Petroleum Inc | Moore, OK 73160-9998 | Oil & Gas Operator | Mar 2015 |
| 587 | Ovation Energy II, LP | Houston, TX 77279 | Oil & Gas Operator | Jun 2011 |
| 588 | Ovintiv Mid-Continent Inc. | The Woodlands, TX 77380-2764 | Oil & Gas Operator | Jan 2024 |
| 589 | Ovintiv USA Inc. | Denver, CO 80202 | Oil & Gas Operator | Apr 2024 |
| 590 | Oxley Petroleum | Tulsa, OK 74119-3609 | Oil & Gas Operator | Jan 2020 |
| 591 | Oxley Petroleum Co | Oklahoma City, OK 73118-1044 | Oil & Gas Operator | Sep 2017 |
| 592 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Apr 2024 |
| 593 | P & P Producing Inc | Midland, TX 79702 | Oil & Gas Operator | Feb 2015 |
| 594 | P O & G Operating LLC | Houston, TX 77057 | Oil & Gas Operator | Apr 2024 |
| 595 | Pacific Enterprise Oil Co USA | Los Angeles, CA 90071-2005 | Oil & Gas Operator | Aug 2012 |
| 596 | Pacific Enterprises Royalty Co | Oklahoma City, OK 73101 | Oil & Gas Operator | Feb 2002 |
| 597 | Pal Kids Inc | Coronado, CA 92118 | Oil & Gas Operator | Nov 2000 |
| 598 | Paleo, Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | Apr 2024 |
| 599 | Paloma Operating Co Inc | | Oil & Gas Operator | Dec 2023 |
| 600 | Pan Western Energy Corporation | Tulsa, OK 74114 | Oil & Gas Operator | Apr 2024 |