| 2501 | Knight Resources, Inc. | | Oil & Gas Operator | Dec 2011 |
| 2502 | Knightsbridge Petroleum Corp. | | Oil Operator | Jul 1991 |
| 2503 | Koch Exploration Company | Houston, TX 77046 | Oil & Gas Operator | Apr 2003 |
| 2504 | Koch Exploration Company, LLC | Denver, CO 80202 | Oil & Gas Operator | Jun 2019 |
| 2505 | Koch Gateway Pipeline Company | | Oil & Gas Operator | Feb 2001 |
| 2506 | Konantz, Inc. | | Oil & Gas Operator | Jan 1995 |
| 2507 | KP Exploration, Inc. | Houston, TX 77002 | Oil & Gas Operator | Apr 1997 |
| 2508 | Kraker & Martin Energy, L.L.C. | Tulsa, OK 74136 | Oil & Gas Operator | Apr 2011 |
| 2509 | Kraker Petroleum Corporation | Tulsa, OK 74136 | Oil & Gas Operator | Jan 1995 |
| 2510 | Kriti Exploration, Inc. | Houston, TX 77002 | Oil & Gas Operator | Oct 2012 |
| 2511 | Kriti Te Energy, Inc | Houston, TX 77079 | Oil & Gas Operator | Oct 2017 |
| 2512 | KV Oil & Gas, Inc. | | Oil & Gas Operator | Dec 2006 |
| 2513 | Kykon Oil & Gas, Inc. | Billings, MT 59103 | Oil & Gas Operator | Feb 2009 |
| 2514 | Kyl-Kat Petroleum | | Oil & Gas Operator | Oct 1996 |
| 2515 | L & J Oil Co. | Borger, TX 79007 | Oil & Gas Operator | Apr 1999 |
| 2516 | L & K Oil | | Oil Operator | Oct 1997 |
| 2517 | L & L Supply | | Oil Operator | Dec 1994 |
| 2518 | L & N Co. | | Oil Operator | Jul 1991 |
| 2519 | L & R Petroleum | Kilgore, TX 75663 | Oil & Gas Operator | Sep 2025 |
| 2520 | L & S Service Corp. | | Oil Operator | Jul 1989 |
| 2521 | L & T Exploration | | Oil & Gas Operator | Dec 1987 |
| 2522 | L & W Oil & Gas, Inc. | | Oil & Gas Operator | May 1994 |
| 2523 | L And C Oil Company | | Oil Operator | Aug 1996 |
| 2524 | L And L Production Company | Skellytown, TX 79080 | Oil & Gas Operator | Sep 1996 |
| 2525 | L E Carpenter Oil & Gas, Inc. | | Oil & Gas Operator | Sep 1985 |
| 2526 | L L & H E Kidd | | Gas Operator | Sep 1990 |
| 2527 | L P C Energy, Inc. | | Oil & Gas Operator | Mar 1985 |
| 2528 | L&N DRLG Co&K.D. Lankford, Jr | | Gas Operator | Aug 2006 |
| 2529 | L'Oil Operating & Management Co., Inc. | | Oil & Gas Operator | Nov 2024 |
| 2530 | L'Oil Operating And MGMT. Co. | | Oil & Gas Operator | Dec 2008 |
| 2531 | L. A. West | | Gas Operator | Feb 2000 |
| 2532 | L. B. Simmons Energy, Inc. | Midland, TX BAD ADDR | Oil & Gas Operator | Oct 1996 |
| 2533 | L. D. McMullan | | Oil Operator | Jun 2023 |
| 2534 | L. E. Gillespie | | Oil Operator | Sep 1984 |
| 2535 | L. E. Hester | | Gas Operator | Oct 2004 |
| 2536 | L. R. Fitzgerald | | Oil & Gas Operator | Feb 2015 |
| 2537 | L. R. Resources II | | Oil & Gas Operator | Feb 1991 |
| 2538 | L. W. Snuffy McCartney | | Oil Operator | Jul 2015 |
| 2539 | L.C. Coon Production Co. | | Oil Operator | Apr 1995 |
| 2540 | L.J. Exploration, Inc. | | Oil & Gas Operator | Dec 2020 |
| 2541 | L.L. Oil Company | Freer, TX 78357 | Oil & Gas Operator | Sep 2025 |
| 2542 | L.S.E. Energy-V.P. Smith | | Oil Operator | Mar 1988 |
| 2543 | La Chalk Gathering System | | Oil Operator | Jan 2006 |
| 2544 | La Coastal Pet.Services Co Inc | | Oil & Gas Operator | Dec 1982 |
| 2545 | La Delta Farms Oil Company LLC | | Oil & Gas Operator | Dec 2024 |
| 2546 | La Gas Dev Corp/Araxas | | Oil & Gas Operator | Dec 2001 |
| 2547 | La Intrastate Gas Co LLC | | Oil Operator | Apr 2004 |
| 2548 | La Mesa Production, Inc. | | Oil & Gas Operator | Apr 2004 |
| 2549 | La. Fete Oil & Gas, Inc. | | Oil & Gas Operator | May 1995 |
| 2550 | La. Gas Production, L.C. | | Gas Operator | Sep 2018 |
| 2551 | La. Land & Expl. Co. | | Oil & Gas Operator | Dec 2010 |
| 2552 | La. Mining & Minerals, Inc. | | Oil & Gas Operator | Jul 2000 |
| 2553 | La. Nap. Inc. Lanlock Res Inc | | Oil Operator | Feb 1995 |
| 2554 | La. Onshore Properties Inc. | | Oil & Gas Operator | Dec 2000 |
| 2555 | La.-TX. Operating, Inc. | | Oil & Gas Operator | May 1998 |
| 2556 | La.Gas Service Expl. Program | | Gas Operator | Dec 1989 |
| 2557 | Labelle Petroleum, Inc. | | Oil & Gas Operator | Oct 1990 |
| 2558 | Lace Operating | Fort Worth, TX 76114 | Oil & Gas Operator | Jun 1997 |
| 2559 | Ladd Petroleum Corp. | Denver, CO 80202 | Oil & Gas Operator | Oct 2004 |
| 2560 | Lafayette Oilfield Contractors, Inc. | | Oil Operator | Dec 2024 |
| 2561 | Lagniappe Interests, Inc. | | Oil & Gas Operator | Dec 2003 |
| 2562 | Lagniappe Operating, LLC | | Oil Operator | Dec 2024 |
| 2563 | Lago Petroleum Co. | | Oil & Gas Operator | Jan 1992 |
| 2564 | Lago VIsta Operating, L.L.C. | | Oil Operator | Dec 2024 |
| 2565 | Lahoma Gas Company | | Gas Operator | Dec 1980 |
| 2566 | Lahoma Operating, Inc. | | Oil & Gas Operator | Jul 2025 |
| 2567 | Lake A, LTD. | | Oil Operator | May 1998 |
| 2568 | Lake Racourci Gath Sys, LLC | | Oil Operator | May 2004 |
| 2569 | Lake Ronel Oil Company | Tyler, TX 75710 | Oil & Gas Operator | Jul 2017 |
| 2570 | Lakeshore Petroleum Corp. | | Oil & Gas Operator | Dec 1992 |
| 2571 | Lakeside Resources | | Oil & Gas Operator | Mar 1989 |
| 2572 | Lamamco Drilling Company | Skiatook, OK 74070 | Oil & Gas Operator | Jun 2025 |
| 2573 | Lamar Hunt | | Oil & Gas Operator | Oct 2003 |
| 2574 | Lamar Hunt Trust Est Etal | | Oil & Gas Operator | Aug 1996 |
| 2575 | Lamar Hunt Trust Est. | | Oil & Gas Operator | Mar 1978 |
| 2576 | Lamar Matlock | | Oil Operator | Jan 2025 |
| 2577 | Lamar Oil & Gas, Inc. | Rockport, TX 78381 | Oil & Gas Operator | Sep 2025 |
| 2578 | Lamar Smith | | Oil Operator | Aug 1991 |
| 2579 | Lamson Petroleum Corporation | | Oil & Gas Operator | Mar 1993 |
| 2580 | Lamson/Crocker Petroleum Corp. | | Oil & Gas Operator | May 1988 |
| 2581 | Lamson/Onshore Petroleum Corp. | | Oil & Gas Operator | Sep 1985 |
| 2582 | Lance Gas & Oil Productions | | Oil & Gas Operator | Jan 2025 |
| 2583 | Lancer Resources Company | | Oil & Gas Operator | Jan 1998 |
| 2584 | Land & Natural Res. Dev., Inc. | | Oil & Gas Operator | Apr 2007 |
| 2585 | Landmark Venture Group No. 1, Inc. | | Oil & Gas Operator | Jan 2025 |
| 2586 | Landmark Venture Group, Inc. | | Oil Operator | Dec 2008 |
| 2587 | Lanford Drilling Co., Inc. | | Oil Operator | Jun 1996 |
| 2588 | Lankford & Nance | | Gas Operator | Dec 2010 |
| 2589 | Lanmarc Resources | | Oil Operator | Dec 2003 |
| 2590 | Lanoco, Inc. | | Oil & Gas Operator | Sep 2002 |
| 2591 | Lapis Operating, Inc. | Houston, TX 77042 | Oil & Gas Operator | Jul 2015 |
| 2592 | Largo Oil Company | Longview, TX 75606 | Oil & Gas Operator | Sep 2025 |
| 2593 | Lark Production, Inc. | | Oil & Gas Operator | Mar 2023 |
| 2594 | Las Services, Inc. | | Oil & Gas Operator | Oct 1997 |
| 2595 | Laser Gas Company I, LLC | | Oil Operator | Aug 2007 |
| 2596 | Lasmo Energy Corporation | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2024 |
| 2597 | Laster Welding And Well Serv, Inc. | | Gas Operator | Jul 2020 |
| 2598 | Lastrada Oil And Gas LTD | | Oil & Gas Operator | May 1992 |
| 2599 | Latex Petroleum Corp. | Houston, TX 77090 | Oil & Gas Operator | Aug 2012 |
| 2600 | Latexo Oil & Gas Co. | | Oil Operator | Sep 1986 |