| 401 | Huston Oil | Woodson, TX 76491 | Oil & Gas Operator | Oct 2010 |
| 402 | HW Operating, LLC | Wichita Falls, TX 76308 | Oil & Gas Operator | May 2025 |
| 403 | I & L Development Co. | Dallas, TX 75219 | Oil & Gas Operator | Mar 1996 |
| 404 | Ickert Enterprises | Olney, TX 76374 | Oil & Gas Operator | May 2025 |
| 405 | Ickert, A. F. Jr. | Olney, TX 76374 | Oil & Gas Operator | Apr 1998 |
| 406 | Ikard, Alan | Electra, TX 76360 | Oil & Gas Operator | May 2025 |
| 407 | Indy Oil, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Feb 2004 |
| 408 | Ipact | Austin, TX 78734 | Oil & Gas Operator | May 2025 |
| 409 | Ipr Energy Partners, L.P. | Bowie, TX 76230 | Oil & Gas Operator | Aug 2014 |
| 410 | Itx Corporation | Dallas, TX 75225 | Oil & Gas Operator | May 2025 |
| 411 | J & A Oil Properties | Olney, TX 76374 | Oil & Gas Operator | Aug 2018 |
| 412 | J & D Services | Graham, TX 76450 | Oil Operator | Feb 2017 |
| 413 | J B J Oil Properties, Inc. | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 414 | J&R Operating | Holliday, TX 76366 | Oil & Gas Operator | Feb 2024 |
| 415 | J. K. J. Company | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 416 | J.H.R. Corporation | Bridgeville, PA 15017 | Oil & Gas Operator | Jul 2001 |
| 417 | J.R. Oil Company | Houston, TX 77007 | Oil & Gas Operator | Jul 2019 |
| 418 | Jackson, D. L., & Son | Jacksboro, TX 76458 | Oil & Gas Operator | May 2001 |
| 419 | Jackson, Jeral W. Inc. | Wichita Falls, TX 76307 | Oil & Gas Operator | May 2004 |
| 420 | James Operating | Iowa Park, TX 76367 | Oil & Gas Operator | May 2025 |
| 421 | James, Deryl | Nocona, TX 76255 | Oil & Gas Operator | May 2025 |
| 422 | JCS Company | Graham, TX 76450 | Oil & Gas Operator | May 2001 |
| 423 | JDL Operating, LLC | Holliday, TX 76366 | Oil & Gas Operator | May 2025 |
| 424 | Jet Black Oil, Inc. | Katy, TX 77494 | Oil Operator | May 2025 |
| 425 | JF Trust | Wichita Falls, TX 76301 | Oil & Gas Operator | Jul 2024 |
| 426 | Jim Production | Jacksboro, TX 76458 | Oil & Gas Operator | Jan 2010 |
| 427 | JL&M Energy, LLC | Wichita Falls, TX 76308 | Oil Operator | May 2025 |
| 428 | JLR Energy | Olney, TX 76374 | Oil & Gas Operator | Dec 2003 |
| 429 | JLW Operations, LLC | Lubbock, TX 79493 | Oil Operator | May 2025 |
| 430 | JMH Production, LLC | Archer City, TX 76351 | Oil & Gas Operator | May 2025 |
| 431 | Johnson & Ernst Operating Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | Sep 2018 |
| 432 | Johnson, Charles | Midland, TX 79702 | Oil & Gas Operator | May 2025 |
| 433 | Johnson, William D. | Fort Worth, TX 76116 | Oil & Gas Operator | Mar 2008 |
| 434 | Joint Resources Company | Fort Worth, TX 76107 | Oil & Gas Operator | May 2025 |
| 435 | Jojon Petroleum Company | Dallas, TX 75219 | Oil & Gas Operator | Feb 2025 |
| 436 | JTL Oil Company LLC | Wichita Falls, TX 76305 | Oil & Gas Operator | May 2025 |
| 437 | Just Oil & Gas, Inc. | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 438 | K & W Vanpelt Company | Portage, OH 43451 | Oil & Gas Operator | May 2025 |
| 439 | K Cubed Resources, L.L.C. | Burleson, TX 76028 | Oil & Gas Operator | May 2025 |
| 440 | K R Well Technology, LLC | Dimmitt, TX 79027 | Oil Operator | May 2025 |
| 441 | K-B Exploration Co. | Houston, TX 77057 | Oil & Gas Operator | May 2025 |
| 442 | Kadane Corporation | Dallas, TX 75205 | Oil & Gas Operator | May 2025 |
| 443 | Kalda Company | Wichita Falls, TX 76307 | Oil & Gas Operator | Dec 1994 |
| 444 | Kampresco Energy, LLC | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 445 | Kar Oil Company | Iowa Park, TX 76367 | Oil & Gas Operator | May 2025 |
| 446 | Karper Oil & Gas Corporation | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 447 | Kasle Energy Inc. | Cross Plains, TX 76443 | Oil & Gas Operator | Mar 2017 |
| 448 | Kelly Mahler Operating, LLC | Graham, TX 76450 | Oil Operator | May 2025 |
| 449 | Kem Energy, Inc. | Katy, TX 77450 | Oil & Gas Operator | May 2025 |
| 450 | Kendrick, Paul W. | Baytown, TX 77520 | Oil & Gas Operator | Sep 2005 |
| 451 | Kennemer, Darrell | Boyd, TX 76023 | Oil Operator | May 2025 |
| 452 | Kimbell Oil Company Of Texas | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2025 |
| 453 | Kincaid Etal, Inc. | Holliday, TX 76366 | Oil Operator | May 2025 |
| 454 | Kincaid, Joey | Holliday, TX 76366 | Oil & Gas Operator | Mar 2005 |
| 455 | Knobloch, Albert | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 456 | Kocana Resources | Ranchos Taos, NM 87557 | Oil & Gas Operator | Jul 1999 |
| 457 | Kramer Operating, LLC | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 458 | Krot Oil Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | May 2025 |
| 459 | KTC Oil Enterprises, LLC | Dallas, TX 75247 | Oil & Gas Operator | May 2025 |
| 460 | Kuran Resources | Wichita Falls, TX 76308 | Oil Operator | May 2025 |
| 461 | Kuykendall, M. C. | Electra, TX 76360 | Oil & Gas Operator | Apr 1995 |
| 462 | L & H Oil Company | Wichita Falls, TX 76301 | Oil & Gas Operator | Oct 1999 |
| 463 | L & J Oil | Gainesville, TX 76240 | Oil & Gas Operator | Nov 2000 |
| 464 | L & S Drilling, Inc. | Kamay, TX 76369 | Oil & Gas Operator | Mar 2016 |
| 465 | L L & M Properties, Inc. | Burkburnett, TX 76354 | Oil & Gas Operator | Aug 2004 |
| 466 | L-R Production | Olney, TX 76374 | Oil & Gas Operator | May 2025 |
| 467 | La Jolla Oil & Gas, Inc. | Frisco, TX 75034 | Oil & Gas Operator | May 2025 |
| 468 | La Mar, Paul W. | Nocona, TX 76255 | Oil & Gas Operator | May 1995 |
| 469 | La Roca Energy, LP | Dallas, TX 75207 | Oil & Gas Operator | May 2024 |
| 470 | Lamar Oil Company | Nocona, TX 76255 | Oil & Gas Operator | Oct 2015 |
| 471 | Lamco Oil, LLC | Nocona, TX 76255 | Oil & Gas Operator | May 2025 |
| 472 | Landrum Petroleum Co., Inc. | Burkburnett, TX 76354 | Oil Operator | Mar 2008 |
| 473 | Landrum West, Inc. | Burkburnett, TX 76354 | Oil & Gas Operator | Dec 1997 |
| 474 | Lankford, Dan L. | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 475 | LC Operating, LLC | Burkburnett, TX 76354 | Oil & Gas Operator | May 2025 |
| 476 | Leclair Operating Co., Inc. | Abilene, TX 79602 | Oil & Gas Operator | May 2025 |
| 477 | Legacy Petroleum Corporation | Dallas, TX 75225 | Oil & Gas Operator | Mar 2019 |
| 478 | Leonard Brothers Operating Co. | Fort Worth, TX 76101 | Oil & Gas Operator | May 2025 |
| 479 | Lewis & Hays | Albany, TX 76430 | Oil & Gas Operator | Feb 2002 |
| 480 | Lewis Operating Company | Holliday, TX 76366 | Oil & Gas Operator | May 2025 |
| 481 | Lewis, William T. | Graham, TX 76450 | Oil & Gas Operator | Mar 2008 |
| 482 | Lindemann, James D. | Holliday, TX 76366 | Oil & Gas Operator | Mar 2008 |
| 483 | Lindemann, Robert Operating | Holliday, TX 76366 | Oil & Gas Operator | May 2025 |
| 484 | Lindemann, W. L., DRLG. Co. | Wichita Falls, TX 76308 | Oil & Gas Operator | Jun 1994 |
| 485 | Lindemann, W.L., Oper. Co., Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Apr 2006 |
| 486 | Lindsay Oil Operations | Wichita Falls, TX 76310 | Oil & Gas Operator | Jun 2010 |
| 487 | Lindsay, Dick | Graham, TX 76450 | Oil & Gas Operator | May 2015 |
| 488 | Lindsay, Robert L. | Wichita Falls, TX 76307 | Oil & Gas Operator | May 1995 |
| 489 | Little, Quintin Company,Inc.,The | Ardmore, OK 73402 | Oil & Gas Operator | May 2025 |
| 490 | Littlepage, Tommy | Graham, TX 76450 | Oil & Gas Operator | May 1996 |
| 491 | Livingston, David Oil Company | Haskell, TX 79521 | Oil & Gas Operator | Aug 2003 |
| 492 | Livingston, F. L. | Megargel, TX 76370 | Oil & Gas Operator | May 2018 |
| 493 | LMH Energy | Wichita Falls, TX 76308 | Oil & Gas Operator | May 2025 |
| 494 | Lode Holdings, LLC | Wichita Falls, TX 76301 | Oil Operator | May 2025 |
| 495 | Lofton, W. A. | Wichita Falls, TX 76301 | Oil & Gas Operator | Jun 1998 |
| 496 | Lonestar Production Services | Graham, TX 76450 | Oil Operator | May 2025 |
| 497 | Lunn, Will | Wichita Falls, TX 76301 | Oil & Gas Operator | Jun 1997 |
| 498 | Lutz And Boyd | Wichita Falls, TX 76308 | Oil & Gas Operator | May 2025 |
| 499 | LW Operating Co. | Wichita Falls, TX 76310 | Oil Operator | May 2025 |
| 500 | Lyon Operating Company Inc.(Iii) | Jacksboro, TX 76458 | Oil & Gas Operator | May 2025 |