| 401 | Powerline Energy Corporation | Arlington, TX 76015 | Oil & Gas Operator | Apr 2024 |
| 402 | Prairie Petroleum, Inc | Plano, TX 75093 | Oil & Gas Operator | May 1999 |
| 403 | Prairie Production | San Antonio, TX 78228 | Oil & Gas Operator | Apr 2024 |
| 404 | Precision Drilling Company, Inc. | Santa Anna, TX 76878 | Oil & Gas Operator | Nov 1995 |
| 405 | Premier Royalties, L.L.C. | Abilene, TX 79608 | Oil & Gas Operator | Apr 2024 |
| 406 | Progas Properties, Inc. | New Braunfels, TX 78132 | Oil & Gas Operator | Apr 2024 |
| 407 | Prospecta Energy Group, Inc. | Brownwood, TX 76801 | Oil Operator | Apr 2024 |
| 408 | Pyramid Production Co. | Abilene, TX 79608 | Oil & Gas Operator | Jun 1994 |
| 409 | Quail Well Service, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Apr 2024 |
| 410 | Quantum Investments | Lubbock, TX 79424 | Oil Operator | Apr 2024 |
| 411 | Quay Valley, Inc. | Midland, TX 79710 | Oil & Gas Operator | Oct 2007 |
| 412 | R & D Operating | Early, TX 76803 | Oil & Gas Operator | Mar 2008 |
| 413 | R & D Operating, Inc. | Early, TX 76802 | Oil & Gas Operator | Apr 2024 |
| 414 | R & L Producing Co., Inc. | Hamilton, TX 76531 | Oil & Gas Operator | Nov 1997 |
| 415 | R & P Operating | Tuscola, TX 79562 | Oil & Gas Operator | Jun 1997 |
| 416 | R & R Well Service | Fort Worth, TX 76120 | Oil & Gas Operator | Jan 2005 |
| 417 | R & R Well Service, Inc. | Arlington, TX 76012 | Oil & Gas Operator | Apr 2024 |
| 418 | R R Operation Inc | Cross Plains, TX 76443 | Oil & Gas Operator | Apr 2004 |
| 419 | Radius Operating, LLC | Round Rock, TX 78664 | Oil & Gas Operator | Apr 2024 |
| 420 | Ratts, Robert V. Inc. | Bedford, TX 76021 | Oil & Gas Operator | Aug 2003 |
| 421 | Rayco Operating, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Apr 2024 |
| 422 | Reach Oil | Brownwood, TX 76801 | Oil & Gas Operator | Apr 2024 |
| 423 | Rebco Oil, Inc. | Desdemona, TX 76445 | Oil Operator | Apr 2024 |
| 424 | Red-Tex Petroleum, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Aug 2003 |
| 425 | Redwood Operating, Inc. | Houston, TX 77058 | Oil & Gas Operator | Apr 2024 |
| 426 | Regent Oil & Gas Company, L.P. | Dallas, TX 75225 | Oil & Gas Operator | Sep 2006 |
| 427 | Reo Operating LLC | Austin, TX 78747 | Oil & Gas Operator | Apr 2024 |
| 428 | Revard Petroleum, L.L.C. | Tulsa, OK 74170 | Oil & Gas Operator | Apr 2024 |
| 429 | Rhodes Drilling Company | Abilene, TX 79608 | Oil & Gas Operator | Sep 2000 |
| 430 | Rhonda Operating Company | Midland, TX 79710 | Oil & Gas Operator | Aug 2017 |
| 431 | Rhyne, J.V. | Cisco, TX 76437 | Oil & Gas Operator | Apr 2024 |
| 432 | Rice Drilling Company | Santa Anna, TX 76878 | Oil & Gas Operator | Apr 2024 |
| 433 | Rice, James D. | Santa Anna, TX 76878 | Oil & Gas Operator | Sep 2007 |
| 434 | Richardson Resources Inc | Brownwood, TX 76801 | Oil & Gas Operator | Apr 2024 |
| 435 | Richardson, Bud II | Graham, TX 76450 | Oil & Gas Operator | Apr 2024 |
| 436 | Richey Operating, Inc. | Tyler, TX 75711 | Oil & Gas Operator | Apr 2024 |
| 437 | Richey, Ray Management Co., Inc. | Fort Worth, TX 76108 | Oil & Gas Operator | Apr 2024 |
| 438 | Richman Petroleum Corp. | Grapevine, TX 76051 | Oil & Gas Operator | Jul 2006 |
| 439 | Rimfire Resources, LLC | Dallas, TX 75201 | Oil & Gas Operator | Apr 2024 |
| 440 | Ringo Rig LLC | Coleman, TX 76834 | Oil & Gas Operator | Apr 2024 |
| 441 | Robertson, French M. Oil Co. | Abilene, TX 79608 | Oil & Gas Operator | Mar 1995 |
| 442 | Rockland Oil Company | Addison, TX 75001 | Oil & Gas Operator | Feb 2024 |
| 443 | Rockwood Resources Inc | Coleman, TX 76834 | Oil & Gas Operator | Apr 2024 |
| 444 | Roco Petroleum, Incorporated | Abilene, TX 79605 | Oil & Gas Operator | Apr 2024 |
| 445 | Rod, Inc. | Coleman, TX 76834 | Oil & Gas Operator | Mar 2008 |
| 446 | Ross Engineering, Inc. | Abilene, TX 79601 | Oil & Gas Operator | Apr 2024 |
| 447 | Ross, Dwight M. DRLG. Co., Inc. | Wichita Falls, TX 76301 | Oil & Gas Operator | Apr 2024 |
| 448 | Rosson, Robert K. | Novice, TX 79538 | Oil & Gas Operator | Aug 2003 |
| 449 | Rough Creek Exploration, Inc. | Santa Anna, TX 76878 | Oil & Gas Operator | Jan 1996 |
| 450 | Royalty Land & Dev. Co., Inc. | Wolfforth, TX 79382 | Oil & Gas Operator | Apr 2024 |
| 451 | Ruby Operating Company, Inc | Clyde, TX 79510 | Oil & Gas Operator | Apr 2024 |
| 452 | Ruthson Energy, Inc. | Judson, TX 75660 | Oil Operator | Apr 2024 |
| 453 | Rwa, LLC | Boyd, TX 76023 | Oil & Gas Operator | Apr 2024 |
| 454 | S & H Resources | Abilene, TX 79605 | Oil & Gas Operator | Apr 2024 |
| 455 | S & J Operating Company | Wichita Falls, TX 76301 | Oil & Gas Operator | Mar 2015 |
| 456 | S & V Operating | Zephyr, TX 76890 | Oil & Gas Operator | Apr 2024 |
| 457 | S. P. Penntex Energy, L.P. | Abilene, TX 79605 | Oil & Gas Operator | May 2003 |
| 458 | S.B. Street Operating, Inc. | Graham, TX 76450 | Oil & Gas Operator | Apr 2024 |
| 459 | Sabre Oil And Gas Corp. | Houston, TX 77063 | Oil & Gas Operator | Apr 2024 |
| 460 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 461 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2024 |
| 462 | San Angelo Cetco, Inc. | San Angelo, TX 76901 | Oil & Gas Operator | Mar 1998 |
| 463 | Santa Anna Operating 3, LLC | Santa Anna, TX 76878 | Oil & Gas Operator | Apr 2024 |
| 464 | Santa Anna Operating Co I, LLC | Abilene, TX 79608 | Oil & Gas Operator | Oct 2018 |
| 465 | Savannah Ross And Company, LLC | Graham, TX 76450 | Oil & Gas Operator | Apr 2024 |
| 466 | Schkade Bros. Operating Company | Abilene, TX 79604 | Oil & Gas Operator | Oct 2021 |
| 467 | Schmid Properties Inc | Hico, TX 76457 | Oil & Gas Operator | Apr 2024 |
| 468 | Scout Energy Management LLC | Dallas, TX 75240 | Oil & Gas Operator | Apr 2024 |
| 469 | Scranton Exploration | Eastland, TX 76448 | Oil & Gas Operator | Apr 2024 |
| 470 | Scully And Smith Oil Corporation | Salado, TX 76571 | Oil & Gas Operator | Feb 1995 |
| 471 | Scully Energy Corporation | Salado, TX 76571 | Oil & Gas Operator | Mar 2012 |
| 472 | Sequoia Energy Resources | Dallas, TX 75207 | Oil & Gas Operator | Apr 2024 |
| 473 | Sequoia Fossil Fuels, Inc. | Albany, TX 76430 | Oil & Gas Operator | Apr 2024 |
| 474 | Service Clearing Corp. | Dallas, TX 75229 | Oil & Gas Operator | Apr 2024 |
| 475 | Seven Cross Operating, LLC | Santa Anna, TX 76878 | Oil & Gas Operator | Apr 2024 |
| 476 | Sha Stephens, Incorporated | Weatherford, TX 76087 | Oil & Gas Operator | Apr 2006 |
| 477 | Shady Oil Co. | Brownwood, TX 76801 | Oil & Gas Operator | Apr 2024 |
| 478 | Shelby, Michael H. | Shreveport, LA 71101 | Oil & Gas Operator | Jan 1994 |
| 479 | Shield Operating Co. | Georgetown, TX 78627 | Oil & Gas Operator | Aug 2003 |
| 480 | Shifflett Operating Company | Snyder, TX 79550 | Oil & Gas Operator | Apr 2024 |
| 481 | Shiloh Oil Company LLC | Williston, FL 32696 | Oil & Gas Operator | Apr 2024 |
| 482 | Shoshone Oil Company | Dallas, TX 75244 | Oil & Gas Operator | May 1994 |
| 483 | Shumate, Jess | Brookesmith, TX 76827 | Oil Operator | Jun 2006 |
| 484 | Simpson Oil & Land Co. | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2024 |
| 485 | Sims, John S. | Lawn, TX 79530 | Oil & Gas Operator | Aug 2003 |
| 486 | Sinclair Exploration Company | Abilene, TX 79604 | Oil & Gas Operator | Nov 1998 |
| 487 | Smalley, Bill | Albany, TX 76430 | Oil & Gas Operator | Jul 2001 |
| 488 | Smith Pipe Of Abilene | Abilene, TX 79608 | Oil & Gas Operator | Apr 2024 |
| 489 | Sojourner Drilling Corporation | Abilene, TX 79604 | Oil & Gas Operator | Apr 2024 |
| 490 | Southern Exploration, Inc. | Fort Worth, TX 76137 | Oil & Gas Operator | Aug 2023 |
| 491 | Southland Royalty Company | Houston, TX 77210 | Oil & Gas Operator | Sep 2011 |
| 492 | Southwest Gas Systems, Inc. | Spring, TX 77379 | Oil & Gas Operator | Apr 2024 |
| 493 | Spartan Oil Corporation | Abilene, TX 79601 | Oil & Gas Operator | Aug 2003 |
| 494 | SRG Oil Corporation | Abilene, TX 79604 | Oil & Gas Operator | Apr 1994 |
| 495 | SRV Oil Co | Coleman, TX 76834 | Oil Operator | Apr 2024 |
| 496 | St. Johns Operating #1 L.P. | Houston, TX 77060 | Oil & Gas Operator | Aug 2023 |
| 497 | Star Production, Inc. | Dallas, TX 75360 | Oil & Gas Operator | Apr 2024 |
| 498 | Stealth, Inc. | Cross Plains, TX 76443 | Gas Operator | Mar 1997 |
| 499 | Stearns Operating Company | Abilene, TX 79604 | Oil & Gas Operator | Oct 1993 |
| 500 | Stephens & Johnson Operating Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | Apr 2024 |