| 501 | Lobodo Inc. | | Oil & Gas Operator | Apr 2003 |
| 502 | Lodi Gas Storage L.L.C. | | Gas Operator | Dec 2023 |
| 503 | Lomax Exploration Company | Roosevelt, UT 84066 | Oil & Gas Operator | Jun 1995 |
| 504 | Lone Eagle LLC | | Oil & Gas Operator | Dec 2003 |
| 505 | Lonestar Foundation Inc. | | Oil Operator | Dec 2008 |
| 506 | Long Beach Oil Development Co | Glendale, CA 91203 | Oil & Gas Operator | Jun 2004 |
| 507 | Longbow LLC | | Oil & Gas Operator | Nov 2023 |
| 508 | Longview Production Company | Dallas, TX 75243-3795 | Oil & Gas Operator | Feb 2024 |
| 509 | Los Angeles Unified School District | | Oil Operator | Dec 2014 |
| 510 | Lyon Canyon Oil Corp. | | Oil & Gas Operator | Dec 1986 |
| 511 | M & B Oil Company | Holliday, TX 76366 | Oil & Gas Operator | Nov 2023 |
| 512 | M & J Operator | | Oil & Gas Operator | Dec 2023 |
| 513 | M. D. & G. Partnership | | Oil & Gas Operator | Dec 1996 |
| 514 | M. H. Whittier Energy LLC | | Oil & Gas Operator | Sep 1996 |
| 515 | M.T. Oil Co. | Copan, OK 74022 | Oil Operator | Nov 2023 |
| 516 | Macpherson Oil Company | | Oil & Gas Operator | Dec 2023 |
| 517 | Macpherson Operating Company L.P. | | Oil & Gas Operator | Dec 2023 |
| 518 | Magness Petroleum Company | | Oil & Gas Operator | Dec 1994 |
| 519 | Manley Energy Resources LLC | | Oil Operator | Jan 2018 |
| 520 | Maranatha Petroleum Inc. | | Oil & Gas Operator | Nov 2023 |
| 521 | Marathon Oil Company | Houston, TX 77024 | Oil & Gas Operator | Feb 2024 |
| 522 | Marathon Oil Company Operator | | Oil & Gas Operator | Dec 1993 |
| 523 | Maria L. Andrade | | Oil Operator | Dec 2006 |
| 524 | Marina Pacifica Oil Company | | Oil & Gas Operator | Dec 1981 |
| 525 | Marlin Pacific Oil & Gas | | Oil & Gas Operator | Dec 2003 |
| 526 | Marlyn Company | | Oil & Gas Operator | Dec 2009 |
| 527 | Marmac Resources Co. | Los Angeles, CA 90027 | Oil & Gas Operator | Mar 2015 |
| 528 | Mary E. Wertalla | | Oil Operator | Dec 1984 |
| 529 | Matrix Oil Corporation | | Oil & Gas Operator | Dec 2023 |
| 530 | Mauro J. Dentino | | Oil Operator | Nov 2023 |
| 531 | Maxim Resources LTD U.S.A. | | Oil & Gas Operator | Dec 1997 |
| 532 | Maxoil Inc. | | Oil & Gas Operator | Dec 2004 |
| 533 | Maxus Exploration Company | Dallas, TX 75201 | Oil & Gas Operator | Jan 1995 |
| 534 | Maya Oil LLC | | Oil Operator | Dec 2023 |
| 535 | McBo Oil Co. | | Oil & Gas Operator | Dec 1996 |
| 536 | McDonald Ranch Partnership | | Oil Operator | Dec 2023 |
| 537 | McFarland Energy, Inc. | New Orleans, LA 70160 | Oil & Gas Operator | Dec 2009 |
| 538 | McKean Bros. | | Oil & Gas Operator | Dec 1997 |
| 539 | McLennan Family Properties LLP | | Oil & Gas Operator | Dec 2021 |
| 540 | McOr Oil & Gas Corp | Houston, TX 77002 | Oil & Gas Operator | Oct 2013 |
| 541 | Medallion Calif Properties Co. | | Oil & Gas Operator | Dec 2003 |
| 542 | Mendell Davis Gas Partners LLC | | Oil & Gas Operator | Dec 2013 |
| 543 | Mentren Corporation | | Gas Operator | Dec 2023 |
| 544 | Meritage Homes Of California Inc. | | Oil Operator | Dec 2020 |
| 545 | Midway-Sunset Investors LLC | | Oil & Gas Operator | Dec 2023 |
| 546 | Mills Oil Co. | | Oil Operator | Dec 1986 |
| 547 | Mission Oil Company | | Oil & Gas Operator | Dec 2023 |
| 548 | Mission Resources | | Oil & Gas Operator | Dec 1991 |
| 549 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 550 | Mitchell Oil | | Oil Operator | Nov 2023 |
| 551 | Mitchell-Grossu Oil Co. | | Oil & Gas Operator | Sep 2023 |
| 552 | Mitchwil Investments LLC | | Oil & Gas Operator | Dec 2019 |
| 553 | Mobil Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2016 |
| 554 | Mobil Oil Exploration & Production North America Inc. | | Oil & Gas Operator | Dec 1996 |
| 555 | Modus Inc. | | Oil & Gas Operator | Dec 2023 |
| 556 | Monterey Resources Inc. | | Oil & Gas Operator | Dec 1997 |
| 557 | Monument Production Inc. | | Oil & Gas Operator | Dec 2011 |
| 558 | Morrison Oil Co. LLC | | Oil & Gas Operator | Nov 2023 |
| 559 | Morton And Dolley | | Oil Operator | Dec 1991 |
| 560 | Mountain VIew Resources LLC | | Oil & Gas Operator | Dec 2023 |
| 561 | Murray-Teague Assoc. | | Oil Operator | Dec 2005 |
| 562 | Mutz Oil Operator | | Oil Operator | Dec 1988 |
| 563 | Naftex Operating Company | | Oil & Gas Operator | Dec 2023 |
| 564 | Nahama & Weagant Energy Company | | Oil & Gas Operator | Dec 1997 |
| 565 | Nana Oil & Gas Inc. | | Oil & Gas Operator | Jan 2018 |
| 566 | Nasco Petroleum L.L.C. | | Oil & Gas Operator | Nov 2023 |
| 567 | National Oil Company | Garden City, KS 67846 | Oil & Gas Operator | Dec 2023 |
| 568 | Natural Gas Corp. Of Calif. | | Oil & Gas Operator | Dec 1987 |
| 569 | Neon Energy Corporation | | Oil Operator | Apr 2014 |
| 570 | New Chaparral Petroleum Inc. | | Oil & Gas Operator | Dec 2005 |
| 571 | New-Lonamen | | Oil & Gas Operator | Dec 2008 |
| 572 | Newbridge Resources, LLC | Houston, TX 77056 | Oil & Gas Operator | Dec 2023 |
| 573 | NGC Energy Co. | | Oil & Gas Operator | May 1989 |
| 574 | NMT Oil Company Inc. | | Oil & Gas Operator | Dec 2023 |
| 575 | Noble Energy Inc | Midland, TX 79706 | Oil & Gas Operator | Apr 2024 |
| 576 | Nordic Oil Company | | Oil & Gas Operator | Dec 1999 |
| 577 | North Of River Sanitary District | | Oil & Gas Operator | Dec 2002 |
| 578 | North Valley Oil & Gas Co. | | Oil & Gas Operator | Dec 1996 |
| 579 | Northern Energy Devel. Co. | | Gas Operator | Dec 1995 |
| 580 | Northern Michigan Expl Co | | Oil & Gas Operator | Jul 1990 |
| 581 | Northwest Petroleum Inc. | | Oil & Gas Operator | Nov 2023 |
| 582 | Nuwi-Bayshore LLC | | Oil & Gas Operator | Dec 1999 |
| 583 | Ny Oil Inc. | | Oil Operator | Dec 2023 |
| 584 | O'Brien-Sill | | Oil & Gas Operator | Dec 2023 |
| 585 | O'Donnell Oil LLC | | Oil & Gas Operator | Nov 2023 |
| 586 | Oakland Petroleum Oper Co., Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Apr 2024 |
| 587 | Occidental Of Elk Hills Inc. | | Oil & Gas Operator | Dec 2014 |
| 588 | Occidental Petroleum Corporation | | Oil & Gas Operator | Dec 2021 |
| 589 | Off Broadway Mineral Rights LLC | | Oil & Gas Operator | Nov 2023 |
| 590 | Ogle Petroleum Inc. | | Oil & Gas Operator | Dec 1989 |
| 591 | Oil Operators Inc. | | Oil & Gas Operator | Nov 2023 |
| 592 | Oil Production Management Inc | Squaw Valley, CA 93675-9725 | Oil & Gas Operator | Dec 2002 |
| 593 | Oil Securities Inc. | | Gas Operator | Dec 2003 |
| 594 | Oil Well Management Co. | | Oil & Gas Operator | Dec 1989 |
| 595 | Ojai Oil Company | Camarillo, CA 93012 | Oil & Gas Operator | Dec 2023 |
| 596 | Old Field Associates | | Oil & Gas Operator | Dec 2023 |
| 597 | Oleksandr Antonyuk | | Oil & Gas Operator | Dec 2018 |
| 598 | Omimex Petroleum Inc | Fort Worth, TX 76120 | Oil & Gas Operator | Aug 2022 |
| 599 | Optima Conservation Resources Exploration LLC | | Oil & Gas Operator | Dec 2023 |
| 600 | Oro Negro Inc. | | Oil & Gas Operator | Dec 2004 |