| 501 | Legacy Energy Services LLC | Stillwater, OK 74074 | Oil & Gas Operator | Dec 2025 |
| 502 | Lenhart Oil Company | Cashion, OK 73016-0188 | Oil & Gas Operator | Jul 2016 |
| 503 | Lewis Oil Operations LLC | Ratliff City, OK 73481 | Oil & Gas Operator | Nov 2025 |
| 504 | Lillard Pipe & Supply Inc | Shawnee, OK 74802-0847 | Oil & Gas Operator | Nov 2014 |
| 505 | Lime Rock Resources II-A, L.P. | Houston, TX 77002 | Oil & Gas Operator | Nov 2025 |
| 506 | Lindenmuth & Associates Inc | Austin, TX 78703 | Oil & Gas Operator | Jun 2025 |
| 507 | Linn Mid-Continent Operating Inc | Houston, TX 77002-3018 | Oil & Gas Operator | Jun 2016 |
| 508 | Lion Petroleum Company | Oklahoma City, OK 73120-4503 | Oil & Gas Operator | Aug 2015 |
| 509 | Little River Energy Company | Drumright, OK 74030 | Oil & Gas Operator | Dec 2025 |
| 510 | Locators Oil And Gas Inc | Guthrie, OK 73044 | Oil & Gas Operator | Oct 2022 |
| 511 | Longfellow Energy, LP | Dallas, TX 75225 | Oil & Gas Operator | Feb 2026 |
| 512 | Lorentz Oil & Gas LLC | Edmond, OK 73034-7266 | Oil & Gas Operator | Nov 2025 |
| 513 | Lu-Ray Petroleum LLC | Oklahoma City, OK 73121-1607 | Oil & Gas Operator | Dec 2025 |
| 514 | Lvi Enterprises Trust | Plano, TX 75093-7789 | Oil & Gas Operator | Nov 2014 |
| 515 | Lynx Energy Company, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Mar 2008 |
| 516 | Lynx Operating Co., Inc. | Dallas, TX 75206 | Oil & Gas Operator | Feb 2026 |
| 517 | M & M Resources Inc | Oklahoma City, OK 73156 | Oil & Gas Operator | Sep 2018 |
| 518 | M & R Enterprises LC | Seminole, OK 74868-0024 | Gas Operator | Mar 2015 |
| 519 | M And V Resources Inc | Crescent, OK 73028 | Oil & Gas Operator | Nov 2025 |
| 520 | M H Oil & Gas LLC | Okeene, OK 73763-0684 | Oil & Gas Operator | Feb 2013 |
| 521 | M M Energy Inc | Oklahoma City, OK 73156 | Oil & Gas Operator | Nov 2025 |
| 522 | M. S. Productions, Inc. | Pittsburg, KS 66762 | Oil & Gas Operator | Nov 2019 |
| 523 | Mack Energy Co. | Duncan, OK 73534 | Oil & Gas Operator | Dec 2025 |
| 524 | Mackellar Inc | Oklahoma City, OK 73116-7101 | Oil & Gas Operator | Dec 2025 |
| 525 | Magic Investments LLC | Edmond, OK 73013 | Oil & Gas Operator | Nov 2025 |
| 526 | Maguire Oil Company | Dallas, TX 75270 | Oil & Gas Operator | Mar 2015 |
| 527 | Malson Oil Company | Crawford, OK 73638 | Oil & Gas Operator | Dec 2016 |
| 528 | Maple Properties Corp | Dallas, TX 75204 | Oil & Gas Operator | Jan 1999 |
| 529 | Marathon Oil Company LLC | Houston, TX 77079 | Oil & Gas Operator | Dec 2025 |
| 530 | Marjo Oil Company | Lockhart, TX 78644 | Oil & Gas Operator | Oct 1999 |
| 531 | Mark Holloway Inc | Oklahoma City, OK 73107-6526 | Oil & Gas Operator | Nov 2025 |
| 532 | Mark L Shidler Inc | Houston, TX 77055 | Oil & Gas Operator | Dec 2025 |
| 533 | Marlin Oil Corporation | Oklahoma City, OK 73113 | Oil & Gas Operator | Nov 2025 |
| 534 | Martin'S Resources LLC | Woodward, OK 73801-5641 | Oil & Gas Operator | Nov 2025 |
| 535 | Maxim Energy Corporation | Baytown, TX 77520 | Oil & Gas Operator | Nov 2025 |
| 536 | McCoy Alex W & Associates | Tulsa, OK 74170 | Oil & Gas Operator | Mar 2009 |
| 537 | McGonigal Dan L | Skiatook, OK 74070 | Oil & Gas Operator | Sep 2024 |
| 538 | MCM Energy Inc | Edmond, OK 73013-8035 | Oil & Gas Operator | Nov 2021 |
| 539 | McMillin C C & Company Inc | Guthrie, OK 73044 | Oil & Gas Operator | Nov 2025 |
| 540 | McQueen Ed & Company Inc | Lindsey, OK 73052 | Oil & Gas Operator | Apr 2014 |
| 541 | McRae & Henry LTD | Golden, CO 80401 | Oil & Gas Operator | May 2022 |
| 542 | Meadowbrook Oil Corporation Of Ok Inc | Del City, OK 73115-3608 | Oil & Gas Operator | Dec 2025 |
| 543 | Mendell Petroleum Corporation | Castle Rock, CO 80104-9045 | Oil & Gas Operator | Sep 2004 |
| 544 | Mep Operating LLC | Houston, TX 77056-2733 | Oil & Gas Operator | Aug 2025 |
| 545 | Mer Resources Inc | Edmond, OK 73013-7662 | Oil & Gas Operator | Mar 2015 |
| 546 | Meridian Oil Production Inc. | Houston, TX 77210 | Oil & Gas Operator | Aug 2024 |
| 547 | Mesa Operating LP | Irving, TX 75039-3746 | Oil & Gas Operator | Oct 2010 |
| 548 | Metropolitan Resources Corp | Tulsa, OK 74169-1734 | Oil & Gas Operator | Mar 2015 |
| 549 | MGF Oil Corporation | Tulsa, OK 74121 | Oil & Gas Operator | Jun 1998 |
| 550 | Mid-Con Central Expl Co | Tulsa, OK 74136 | Oil & Gas Operator | Aug 2014 |
| 551 | Mid-Con Energy Operating, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | May 2020 |
| 552 | Mid-Con Energy Operating, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Dec 2025 |
| 553 | Midwest Energy Corporation | Tulsa, OK 74105-6083 | Oil & Gas Operator | Aug 2016 |
| 554 | Midwest Enterprises Inc | Cashion, OK 73016-9626 | Oil & Gas Operator | Apr 2025 |
| 555 | Midwest Pipe & Supply Company | Oklahoma City, OK 73154-0245 | Oil & Gas Operator | Dec 2008 |
| 556 | Miller Exploration Company | Tulsa, OK 74136-1020 | Oil & Gas Operator | Mar 2015 |
| 557 | Miller Oil & Gas Co | Okmulgee, OK 74447 | Oil & Gas Operator | Oct 2017 |
| 558 | Miracle Production Inc | Yukon, OK 73085-0680 | Oil & Gas Operator | Jun 2007 |
| 559 | MLC Resources LLC | Kingfisher, OK 73750-0364 | Oil & Gas Operator | Nov 2025 |
| 560 | Monroe Natural Gas Inc | Norman, OK 73071 | Oil & Gas Operator | Nov 2025 |
| 561 | Montgomery Oil & Gas Expl Inc | Tulsa, OK 74170-1884 | Oil & Gas Operator | Mar 2005 |
| 562 | Monty L Hott Production Corporation | Oklahoma City, OK 73142 | Oil & Gas Operator | Nov 2025 |
| 563 | Moore & Moore Energy Inc | Purcell, OK 73080-0674 | Oil & Gas Operator | Dec 2012 |
| 564 | Morgan David E | Enid, OK 73702-3525 | Oil & Gas Operator | Sep 2016 |
| 565 | Mott Energy LLC | Riverview, FL 33569-6702 | Oil & Gas Operator | Sep 2024 |
| 566 | Mott Petroleum Corporation | Sugar Land, TX 77487 | Oil & Gas Operator | Aug 2024 |
| 567 | Mud Operations Inc | Ames, OK 73718-9501 | Oil & Gas Operator | Nov 2025 |
| 568 | Muras Energy Inc | Edmond, OK 73013 | Oil & Gas Operator | Nov 2025 |
| 569 | Murchison Oil & Gas Inc | Plano, TX 75024 | Oil & Gas Operator | Aug 2020 |
| 570 | Mustang Fuel Corp. Of Oklahoma | Oklahoma City, OK 73106 | Oil & Gas Operator | Nov 2016 |
| 571 | Mustang Fuel Corporation | Oklahoma City, OK 73114 | Oil & Gas Operator | Dec 2025 |
| 572 | Mustang Gas Products LLC | Oklahoma City, OK 73114-7406 | Oil & Gas Operator | Sep 2022 |
| 573 | MW Petroleum Corporation | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |
| 574 | National Cooperative RFG Assoc | McPherson, KS 67460-1404 | Oil & Gas Operator | Oct 2025 |
| 575 | National Energy Group Inc | Dallas, TX 75206 | Oil & Gas Operator | Sep 2014 |
| 576 | National Oil Company | Garden City, KS 67846 | Oil & Gas Operator | Jun 2024 |
| 577 | Natural Gas Pipeline Co Of Am LLC | Downers Grove, IL 60515-3708 | Oil & Gas Operator | Mar 2015 |
| 578 | Nbi Services, Inc. | Tulsa, OK 74159 | Oil & Gas Operator | Feb 2026 |
| 579 | Neg Operating LLC | Oklahoma City, OK 73101 | Oil & Gas Operator | Aug 2025 |
| 580 | Nelson Exploration Corporation | Cleveland, OK 74020-5725 | Oil & Gas Operator | Nov 2025 |
| 581 | Nichols, Irl. A. Trust B | Duncan, OK 73534 | Oil & Gas Operator | Sep 2000 |
| 582 | Nielson & Associates, Inc | Cody, WY 82414 | Oil & Gas Operator | Feb 2016 |
| 583 | Noble Energy Inc | Midland, TX 79706 | Oil & Gas Operator | Feb 2026 |
| 584 | Noble Energy Production Inc | Houston, TX 77067 | Oil & Gas Operator | Feb 2026 |
| 585 | Noco Investment Company Inc | Tulsa, OK 74159-0470 | Oil & Gas Operator | Mar 2005 |
| 586 | North Central Casing Puller Inc | Graham, TX 76450 | Oil & Gas Operator | Jan 1999 |
| 587 | North Lake Resources LLC | Oklahoma City, OK 73132 | Oil & Gas Operator | Feb 2026 |
| 588 | Northwest Oil Company | Dallas, TX 75204 | Oil & Gas Operator | Jun 2014 |
| 589 | Nova Energy Corporation | Denver, CO 80201 | Oil & Gas Operator | Jun 2003 |
| 590 | NWM Operating Inc | Okeene, OK 73763 | Oil & Gas Operator | Nov 2025 |
| 591 | O G & E | Oklahoma City, OK 73124 | Oil & Gas Operator | Feb 2014 |
| 592 | O K Swabbing Inc | Hennessey, OK 73742 | Oil & Gas Operator | Nov 2025 |
| 593 | O'Neill Properties, LTD. | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 594 | Oak Valley SWD LLC | Enid, OK 73703-4637 | Oil Operator | Aug 2022 |
| 595 | Odessa Natural Corporation | | Oil & Gas Operator | Dec 1991 |
| 596 | Odessa Oil Investment Co., Inc. | Odessa, TX 79762 | Oil & Gas Operator | Nov 2016 |
| 597 | Oexco, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2015 |
| 598 | Ofs-Tulsa Corporation | Fort Worth, TX 76102 | Oil & Gas Operator | Feb 1997 |
| 599 | Oil Producers, Inc. Of Kansas | Wichita, KS 67206 | Oil & Gas Operator | Feb 2026 |
| 600 | Okie Crude Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2025 |