| 401 | Inca Oil Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | May 2009 |
| 402 | Indian Oil Company | Gainesville, TX 76241 | Oil & Gas Operator | Jun 2026 |
| 403 | Intergy Production LLC | Edmond, OK 73083 | Oil & Gas Operator | Mar 2026 |
| 404 | Internorth Inc | Tulsa, OK 74136 | Oil & Gas Operator | Apr 2014 |
| 405 | Investment Equipment LLC | FT Morgan, CO 80701 | Oil & Gas Operator | Mar 2026 |
| 406 | J & S Of Enid Inc | Enid, OK 73701 | Oil & Gas Operator | Jul 2019 |
| 407 | J & T Operating Inc | Norman, OK 73070-1736 | Oil & Gas Operator | Feb 2012 |
| 408 | J L Hajek Enterprises LLC | Ames, OK 73718 | Oil & Gas Operator | Nov 2025 |
| 409 | J O C Operating Inc | Fort Worth, TX 76102-6823 | Oil & Gas Operator | Feb 2021 |
| 410 | J O MC Oil & Gas Inc | Maud, OK 74854 | Oil & Gas Operator | Apr 1999 |
| 411 | Jaco, Troy Inc. | Sherman, TX 75091 | Oil & Gas Operator | Jun 2026 |
| 412 | James Larry | Guthrie, OK 73044-9622 | Oil & Gas Operator | Feb 2026 |
| 413 | James Lawrence E Estate Of | Crescent, OK 73028-9304 | Oil & Gas Operator | Nov 2021 |
| 414 | January Investments LLC | Norman, OK 73069-8224 | Oil & Gas Operator | Mar 2026 |
| 415 | Jay Petroleum Inc | Oklahoma City, OK 73154-0526 | Oil & Gas Operator | Mar 2019 |
| 416 | Jec Operating LLC | Oklahoma City, OK 73114-2717 | Oil & Gas Operator | Feb 2026 |
| 417 | Jegeroil Corp | New York, NY 10036 | Oil & Gas Operator | Aug 2000 |
| 418 | Jerry Sanner Oil Properties Inc | Enid, OK 73701 | Oil & Gas Operator | Mar 2026 |
| 419 | Jet Oil Co12/Ofb See 18649 | | Oil & Gas Operator | Jul 2007 |
| 420 | Jhatco Inc | Enid, OK 73701 | Oil & Gas Operator | Mar 2026 |
| 421 | JKB Resources LLC | Stigler, OK 74462 | Oil & Gas Operator | Mar 2026 |
| 422 | JMK Energy Company | Hennessey, OK 73742-0518 | Oil & Gas Operator | Jun 2016 |
| 423 | JN Production LLP | Guthrie, OK 73028 | Oil & Gas Operator | Feb 2026 |
| 424 | Johnson E Lyle | Oklahoma City, OK 73142 | Oil & Gas Operator | Feb 2026 |
| 425 | Johnson Exploration Company | Oklahoma City, OK 73102-7008 | Oil & Gas Operator | Jun 2015 |
| 426 | Johnson Oil Company | Duncan, OK 73533 | Oil Operator | Mar 2026 |
| 427 | Jojon Petroleum Company | Dallas, TX 75219 | Oil & Gas Operator | Feb 2026 |
| 428 | Jordan Oil & Gas Company | Healdsburg, CA 95448-1919 | Oil & Gas Operator | Mar 1995 |
| 429 | Jrhop Inc | Norman, OK 73072-4615 | Oil & Gas Operator | Dec 2015 |
| 430 | K & F Oil Co. | Olney, TX 76374 | Oil & Gas Operator | Dec 2021 |
| 431 | K & M Oil Company LLC | Hennessey, OK 73742 | Oil & Gas Operator | Feb 2026 |
| 432 | K S Oil Company Inc | Norman, OK 73072-7480 | Oil & Gas Operator | Mar 2026 |
| 433 | Kahan Louis | Tulsa, OK 74101 | Oil & Gas Operator | May 1994 |
| 434 | Kaiser Investments | Sand Springs, OK 74063 | Oil & Gas Operator | Sep 2003 |
| 435 | Kaiser-Francis Oil Company | Tulsa, OK 74121 | Oil & Gas Operator | Jun 2026 |
| 436 | Kaneb Operating Company | Dallas, TX 75265-0283 | Oil & Gas Operator | Dec 1995 |
| 437 | Keener Oil & Gas Company | Tulsa, OK 74119-4416 | Oil & Gas Operator | Mar 2026 |
| 438 | Keener Oil Company | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2018 |
| 439 | Keith F Walker Oil & Gas Company LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Mar 2026 |
| 440 | Kelle Day Oil Producers Inc | Braman, OK 74632-9147 | Oil & Gas Operator | Dec 2023 |
| 441 | Keno Oil & Gas Inc | Hennessey, OK 73742 | Oil & Gas Operator | Jan 1995 |
| 442 | Kepco. Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2015 |
| 443 | Kerr McGee Rocky MTN Corp | Denver, CO 80202-5736 | Oil & Gas Operator | Mar 2015 |
| 444 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | Feb 2026 |
| 445 | Kerr-McGee Refining Corp | Oklahoma City, OK 73125 | Oil & Gas Operator | Jun 2007 |
| 446 | Key Energy Corporation | Enid, OK 73702-5349 | Oil & Gas Operator | Oct 2017 |
| 447 | Key Energy Services Inc | Midland, TX 79705-5540 | Oil Operator | Jan 2008 |
| 448 | Kibtec Oil & Gas Inc | Cashion, OK 73016 | Oil & Gas Operator | Aug 2024 |
| 449 | Kingfisher CSG Pullr & Const Inc | Hennessey, OK 73742-0024 | Oil & Gas Operator | Apr 2014 |
| 450 | Kingfisher Resources Inc | Clinton, OK 73601 | Oil & Gas Operator | Mar 2026 |
| 451 | Kirkpatrick Oil Company | Nichols Hill, OK 73116 | Oil & Gas Operator | Jun 2026 |
| 452 | Koby Oil Company LLC | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2026 |
| 453 | Koch Oil Company | | Oil & Gas Operator | May 2017 |
| 454 | Kodiak Oil & Gas Exploration Inc | Oklahoma City, OK 73134-1046 | Oil & Gas Operator | Feb 2026 |
| 455 | Kodiak Oil & Gas Inc | Muenster, TX 76252 | Oil & Gas Operator | Jun 2026 |
| 456 | KWB Oil Property Management Inc | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2026 |
| 457 | L & N Exploration Inc | | Oil & Gas Operator | Jul 2013 |
| 458 | L.E. Jones Operating, Inc. | Duncan, OK 73534 | Oil & Gas Operator | Mar 2026 |
| 459 | Lamamco Drilling Company | Skiatook, OK 74070 | Oil & Gas Operator | Feb 2026 |
| 460 | Lance Ruffel Oil & Gas LLC | Oklahoma City, OK 73102-5632 | Oil & Gas Operator | Mar 2026 |
| 461 | Lancer Energy Corporation | Oklahoma City, OK 73132-5903 | Oil & Gas Operator | May 2015 |
| 462 | Lario Oil & Gas Company | Odessa, TX 79762 | Oil & Gas Operator | Jun 2026 |
| 463 | Las Colinas Oil Corp. | Irving, TX 75062 | Oil & Gas Operator | Mar 2015 |
| 464 | Laurel Operating Company | Stillwater, OK 74074-3025 | Oil & Gas Operator | Feb 2026 |
| 465 | Lawrence James LLC | Guthrie, OK 73044-9622 | Oil & Gas Operator | Feb 2026 |
| 466 | Lawrence James Oil Prop Inc | Catoosa, OK 74015 | Oil & Gas Operator | Feb 2012 |
| 467 | LCB Resources LLC | Kingfisher, OK 73750-2322 | Oil & Gas Operator | Mar 2026 |
| 468 | Le Norman Energy Corporation | Duncan, OK 73534 | Oil & Gas Operator | Nov 2014 |
| 469 | Leasehold Management Corp | Oklahoma City, OK 73107 | Oil & Gas Operator | Nov 2024 |
| 470 | Leeman Energy Corporation | Oklahoma City, OK 73118-1802 | Oil & Gas Operator | Mar 2015 |
| 471 | Legacy - M & K Corporation | Dallas, TX 75231-0969 | Oil & Gas Operator | Jan 2025 |
| 472 | Legacy Energy Services LLC | Stillwater, OK 74074 | Oil & Gas Operator | Mar 2026 |
| 473 | Legacy Reserves Operating LP | Denver, CO 80201 | Oil & Gas Operator | Jun 2026 |
| 474 | Leigh Operating Co | Dallas, TX 75205 | Oil & Gas Operator | Mar 2008 |
| 475 | Lewis Oil Corp. | Stillwater, OK 74076 | Oil & Gas Operator | Feb 2026 |
| 476 | Liberty Operating Inc | Norman, OK 73069-8225 | Oil & Gas Operator | Dec 2024 |
| 477 | Likins-Foster Honolulu Corp | Foster City, CA 94404 | Oil & Gas Operator | Feb 2015 |
| 478 | Lime Rock Resources II-A, L.P. | Houston, TX 77002 | Oil & Gas Operator | Feb 2026 |
| 479 | Lindenmuth & Associates Inc | Austin, TX 78703 | Oil & Gas Operator | Jun 2025 |
| 480 | Lion Petroleum Company | Oklahoma City, OK 73120-4503 | Oil & Gas Operator | Aug 2015 |
| 481 | Little River Energy Company | Drumright, OK 74030 | Oil & Gas Operator | Mar 2026 |
| 482 | Littrell Chemical Inc | Cleo Springs, OK 73729 | Oil & Gas Operator | Jan 2005 |
| 483 | Lobar Oil Co LLC | Edmond, OK 73013 | Oil & Gas Operator | Feb 2026 |
| 484 | Lobo Energy, Inc. | Laredo, TX 78044 | Oil & Gas Operator | Nov 1996 |
| 485 | Locators Oil And Gas Inc | Guthrie, OK 73044 | Oil & Gas Operator | Oct 2022 |
| 486 | London William W | Oklahoma City, OK 73116 | Oil & Gas Operator | Nov 2015 |
| 487 | London William W Inc | Oklahoma City, OK 73116-5116 | Oil & Gas Operator | Apr 2016 |
| 488 | Long Engineering Company Inc | Oklahoma City, OK 73112-7769 | Oil Operator | Jun 2008 |
| 489 | Longbranch Oil Company | Oklahoma City, OK 73154-0735 | Oil & Gas Operator | Mar 2018 |
| 490 | Lord Enterprises Inc | Oklahoma City, OK 73106-5050 | Oil & Gas Operator | Sep 2000 |
| 491 | Lu-Ray Petroleum LLC | Oklahoma City, OK 73121-1607 | Oil & Gas Operator | Mar 2026 |
| 492 | Luween Energy LLC | Oklahoma City, OK 73128 | Oil & Gas Operator | Feb 2026 |
| 493 | M & M Resources Inc | Oklahoma City, OK 73156 | Oil & Gas Operator | Sep 2018 |
| 494 | M And V Resources Inc | Crescent, OK 73028 | Oil & Gas Operator | Feb 2026 |
| 495 | M M Energy Inc | Oklahoma City, OK 73156 | Oil & Gas Operator | Feb 2026 |
| 496 | Mack Energy Co. | Duncan, OK 73534 | Oil & Gas Operator | Mar 2026 |
| 497 | Mackellar Inc | Oklahoma City, OK 73116-7101 | Oil & Gas Operator | Mar 2026 |
| 498 | Magaw & Zimmer | Perry, OK 73077-1055 | Oil & Gas Operator | Aug 2013 |
| 499 | Maggard Oil Co Inc | Manford, OK 74044 | Oil & Gas Operator | Sep 1997 |
| 500 | Malson Oil Company | Crawford, OK 73638 | Oil & Gas Operator | Dec 2016 |