| 401 | Inca Oil Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | May 2009 |
| 402 | Indian Oil Company | Gainesville, TX 76241 | Oil & Gas Operator | May 2025 |
| 403 | Interstate Explorations LLC | Houston, TX 77010 | Oil & Gas Operator | May 2025 |
| 404 | Investment Equipment LLC | FT Morgan, CO 80701 | Oil & Gas Operator | Mar 2025 |
| 405 | Investors Resources Corp | Edmond, OK 73034 | Oil & Gas Operator | Mar 2025 |
| 406 | Invoil, Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | May 2025 |
| 407 | Itr Petroleum Inc | Houston, TX 77002 | Oil & Gas Operator | Apr 1998 |
| 408 | J & S Of Enid Inc | Enid, OK 73701 | Oil & Gas Operator | Jul 2019 |
| 409 | J B Energy, Inc. | Denton, TX 76206 | Oil & Gas Operator | Aug 2018 |
| 410 | J-Brex Company | Amarillo, TX 79101 | Oil & Gas Operator | May 2025 |
| 411 | J-W Operating Company | Christoval, TX 76935 | Oil & Gas Operator | May 2025 |
| 412 | Jackson L B Production Co | Tulsa, OK 74193-0001 | Oil & Gas Operator | Aug 2013 |
| 413 | January Investments LLC | Norman, OK 73069-8224 | Oil & Gas Operator | Mar 2025 |
| 414 | JCR, Jr - Operating, Inc. | Amarillo, TX 79114 | Oil & Gas Operator | Apr 2022 |
| 415 | JCT #1 LTD | Fairview, OK 73737-9614 | Oil Operator | Sep 2006 |
| 416 | Jebito Farm LLC | Oklahoma City, OK 73162-6249 | Oil & Gas Operator | Feb 2025 |
| 417 | Jeda Kini Production Co LLC | Hays, KS 67601-3659 | Oil & Gas Operator | Mar 2008 |
| 418 | Jerry Sanner Oil Properties Inc | Enid, OK 73701 | Oil & Gas Operator | Mar 2025 |
| 419 | Jet Oil Co12/Ofb See 18649 | | Oil & Gas Operator | Jul 2007 |
| 420 | Jhatco Inc | Enid, OK 73701 | Oil & Gas Operator | Mar 2025 |
| 421 | Jico Exploration Inc | Oklahoma City, OK 73118 | Oil & Gas Operator | Nov 2004 |
| 422 | JKB Resources LLC | Stigler, OK 74462 | Oil & Gas Operator | Feb 2025 |
| 423 | JN Production LLP | Guthrie, OK 73028 | Oil & Gas Operator | Mar 2025 |
| 424 | Jobe Oil & Gas | Comanche, OK 73529-0244 | Oil & Gas Operator | Mar 2025 |
| 425 | Johnson E Lyle | Oklahoma City, OK 73142 | Oil & Gas Operator | Feb 2025 |
| 426 | Jolen Operating Company | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2025 |
| 427 | Jones & Pellow Oil Co | Oklahoma City, OK 73118-1115 | Oil & Gas Operator | Feb 2015 |
| 428 | Jones Energy LLC | Oklahoma City, OK 73134 | Oil & Gas Operator | Feb 2025 |
| 429 | Jones Oil Company LLC (The) | Duncan, OK 73533-4995 | Oil & Gas Operator | Mar 2025 |
| 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 | Jan 2025 |
| 432 | K Energy Inc | Mannford, OK 74044-3023 | Oil & Gas Operator | May 2013 |
| 433 | K G Operating | Hennessey, OK 73742 | Oil & Gas Operator | May 1999 |
| 434 | K S Oil Company Inc | Norman, OK 73072-7480 | Oil & Gas Operator | Feb 2025 |
| 435 | Kaiser-Francis Oil Company | Tulsa, OK 74121 | Oil & Gas Operator | May 2025 |
| 436 | KC Resources Inc | Snowmass VLG., CO 81615 | Oil & Gas Operator | Feb 2025 |
| 437 | KCS Medallion Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Nov 2018 |
| 438 | KCS Resources LLC | Houston, TX 77027 | Oil & Gas Operator | Feb 2017 |
| 439 | Kennedy & Mitchell, Inc. | Houston, TX 77084 | Oil & Gas Operator | Aug 2013 |
| 440 | Kenneth W. Cory, LTD. | Bellaire, TX 77401 | Oil & Gas Operator | Mar 2025 |
| 441 | Kenworthy Operating Company | Tulsa, OK 74132 | Oil & Gas Operator | May 2009 |
| 442 | Kerr McGee Rocky MTN Corp | Denver, CO 80202-5736 | Oil & Gas Operator | Mar 2015 |
| 443 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | Mar 2025 |
| 444 | Kerr-McGee Oil & Gas Onshore LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2017 |
| 445 | Kerr-McGee Oil & Gas Onshore LP | Houston, TX 77046 | Oil & Gas Operator | May 2025 |
| 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 | Kingfisher CSG Pullr & Const Inc | Hennessey, OK 73742-0024 | Oil & Gas Operator | Apr 2014 |
| 449 | Kingfisher Resources Inc | Clinton, OK 73601 | Oil & Gas Operator | Mar 2025 |
| 450 | Kirkpatrick Oil Company | Nichols Hill, OK 73116 | Oil & Gas Operator | May 2025 |
| 451 | Klingensmith Fred T Etal | Sapulpa, OK 74066 | Oil & Gas Operator | Nov 2007 |
| 452 | KNG Producers | Dumas, TX 79029 | Oil & Gas Operator | Oct 2009 |
| 453 | Koch Oil Company | | Oil & Gas Operator | May 2017 |
| 454 | Kodiak Oil & Gas Exploration Inc | Oklahoma City, OK 73134-1046 | Oil & Gas Operator | Feb 2025 |
| 455 | Kodiak Oil & Gas Inc | Muenster, TX 76252 | Oil & Gas Operator | May 2025 |
| 456 | KP Exploration, Inc. | Houston, TX 77002 | Oil & Gas Operator | Apr 1997 |
| 457 | KPL Production Company LLC | Oklahoma City, OK 73112-4709 | Oil & Gas Operator | Feb 2017 |
| 458 | KRS Oil Company | Frisco, TX 75034 | Oil & Gas Operator | Apr 2020 |
| 459 | KT Energy Inc | Enid, OK 73702-2365 | Oil & Gas Operator | Feb 2025 |
| 460 | L & B Oil Company Inc | Houston, TX 77019-3115 | Oil & Gas Operator | Mar 2025 |
| 461 | L.L. Oil Company | Freer, TX 78357 | Oil & Gas Operator | May 2025 |
| 462 | Ladd Petroleum Corp. | Denver, CO 80202 | Oil & Gas Operator | Oct 2004 |
| 463 | Ladder Energy Company | Tulsa, OK 74120-4281 | Oil & Gas Operator | Jan 2018 |
| 464 | Lagoon Water Logistics LLC | Oklahoma City, OK 73103 | Oil Operator | Jul 2024 |
| 465 | Lamamco Drilling Company | Skiatook, OK 74070 | Oil & Gas Operator | Feb 2025 |
| 466 | Lamb Alan L | Oklahoma City, OK 73120-7824 | Oil & Gas Operator | Feb 2020 |
| 467 | Lance Ruffel Oil & Gas LLC | Oklahoma City, OK 73102-5632 | Oil & Gas Operator | Mar 2025 |
| 468 | Landmark Energy LLC | Seminole, OK 74868 | Oil & Gas Operator | Mar 2025 |
| 469 | Landmark Exploration Co | Tulsa, OK 74103 | Oil & Gas Operator | Oct 2013 |
| 470 | Lariat Petroleum Inc | Tulsa, OK 74119 | Oil & Gas Operator | Sep 2024 |
| 471 | Larkspur Operating LLC | Oklahoma City, OK 73034 | Oil & Gas Operator | Mar 2025 |
| 472 | Latigo Oil And Gas Inc | Woodward, OK 73801 | Oil & Gas Operator | Mar 2025 |
| 473 | Laurco Energies,Inc | | Oil & Gas Operator | Oct 2024 |
| 474 | Laurel Operating Company, Inc. | Stillwater, OK 74074-3025 | Oil & Gas Operator | Mar 2025 |
| 475 | Lawrence, C. F. & Assoc. Inc. | Lubbock, TX 79401 | Oil & Gas Operator | May 2025 |
| 476 | LCB Resources LLC | Kingfisher, OK 73750-2322 | Oil & Gas Operator | Mar 2025 |
| 477 | Le Norman Energy Corporation | Duncan, OK 73534 | Oil & Gas Operator | Nov 2014 |
| 478 | Leeman Don J | Oklahoma City, OK 73112 | Oil & Gas Operator | Sep 1998 |
| 479 | Legacy Energy Services LLC | Stillwater, OK 74074 | Oil & Gas Operator | Mar 2025 |
| 480 | Lime Rock Resources II-A, L.P. | Houston, TX 77002 | Oil & Gas Operator | Feb 2025 |
| 481 | Lindenmuth & Associates Inc | Austin, TX 78703 | Oil & Gas Operator | Aug 2024 |
| 482 | Linn Mid-Continent Operating Inc | Houston, TX 77002-3018 | Oil & Gas Operator | Jun 2016 |
| 483 | Littrell Chemical Inc | Cleo Springs, OK 73729 | Oil & Gas Operator | Jan 2005 |
| 484 | Lobo Exploration Company | Yukon, OK 73099 | Oil & Gas Operator | Feb 2025 |
| 485 | Lorentz Oil & Gas LLC | Edmond, OK 73034-7266 | Oil & Gas Operator | Feb 2025 |
| 486 | Lre Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Nov 2016 |
| 487 | LX4, LLC | | Oil Operator | Mar 2025 |
| 488 | M & D Pumping Service Inc | Ringwood, OK 73768-3415 | Oil & Gas Operator | Oct 2024 |
| 489 | M And V Resources Inc | Crescent, OK 73028 | Oil & Gas Operator | Feb 2025 |
| 490 | M M & M Resources Inc | Wetumka, OK 74883 | Oil & Gas Operator | Apr 2020 |
| 491 | M M Energy, Inc. | Oklahoma City, OK 73156 | Oil & Gas Operator | Feb 2025 |
| 492 | M M Resources, Inc. | Oklahoma City, OK 73156 | Oil & Gas Operator | Sep 2018 |
| 493 | Mack Energy Co. | Duncan, OK 73534 | Oil & Gas Operator | Mar 2025 |
| 494 | Mack Oil Company | Duncan, OK 73534 | Oil & Gas Operator | Nov 2000 |
| 495 | Mackellar Inc | Oklahoma City, OK 73116-7101 | Oil & Gas Operator | Mar 2025 |
| 496 | Magnum Energy Inc | Norman, OK 73072-2403 | Oil & Gas Operator | Mar 2025 |
| 497 | Maguire Oil Company | Dallas, TX 75270 | Oil & Gas Operator | Mar 2015 |
| 498 | Malson Oil Company | Crawford, OK 73638 | Oil & Gas Operator | Dec 2016 |
| 499 | Manuel Corporation | Wichita, KS 67206 | Oil & Gas Operator | Mar 2025 |
| 500 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Mar 2025 |