| 401 | Rio Bravo Royalty Co. | Bandera, TX 78003 | Oil & Gas Operator | Aug 2003 |
| 402 | Rio Energy | Houston, TX 77067 | Oil Operator | Apr 2024 |
| 403 | Rio Grand Exploration, LLC | San Antonio, TX 78216 | Oil & Gas Operator | Apr 2024 |
| 404 | Rio Grande Drilling Company | San Antonio, TX 78212 | Oil & Gas Operator | Dec 1999 |
| 405 | Rio Grande E&P II, LLC | Houston, TX 77092 | Gas Operator | Apr 2024 |
| 406 | Rio Grande E&P, LLC | Houston, TX 77024 | Gas Operator | May 2022 |
| 407 | Rio Interstate Oil, Inc. | Oklahoma City, OK 73189 | Oil & Gas Operator | Sep 1994 |
| 408 | Rio O & P LLC | Pasadena, TX 77504 | Oil Operator | Apr 2024 |
| 409 | Rio Oil And Gas (Permian) II,LLC | The Woodlands, TX 77382 | Oil & Gas Operator | Apr 2024 |
| 410 | Rio Petroleum, Inc. | Amarillo, TX 79102 | Oil & Gas Operator | Apr 2024 |
| 411 | Rio-Tex, Inc. | San Antonio, TX 78217 | Oil & Gas Operator | Apr 2024 |
| 412 | Rippy Branch Oil Co. | Grandfalls, TX 79742 | Oil & Gas Operator | Apr 2022 |
| 413 | Rippy Oil Company | Tyler, TX 75702 | Oil & Gas Operator | Apr 2024 |
| 414 | Riptide Energy LLC | Austin, TX 78701 | Oil & Gas Operator | Apr 2024 |
| 415 | Risco La Sara Operations, LLC | Houston, TX 77056 | Oil & Gas Operator | Aug 2014 |
| 416 | Rise Petroleum Investments LLC | Spring, TX 77386 | Oil & Gas Operator | Apr 2024 |
| 417 | Riseden Services, Inc. | Houston, TX 77256 | Oil & Gas Operator | Sep 1997 |
| 418 | Rising Star Energy PTR, L.L.C. | Dallas, TX 75219 | Oil & Gas Operator | Apr 2024 |
| 419 | Rising Star Energy, L.L.C. | Dallas, TX 75219 | Oil & Gas Operator | Aug 2006 |
| 420 | Rising Star Petroleum, L.L.C. | Dallas, TX 75219 | Oil & Gas Operator | Apr 2010 |
| 421 | Rister Oil&Gas International LLC | Eastland, TX 76448 | Oil & Gas Operator | Apr 2024 |
| 422 | Rister, Dewey | Avoca, TX 79503 | Oil & Gas Operator | Apr 2024 |
| 423 | Ritchie, H. G. Jr. | Taft, TX 78390 | Oil & Gas Operator | Apr 2024 |
| 424 | Rittenhouse Oil & Gas Co. | Midland, TX 79702 | Oil & Gas Operator | Apr 2024 |
| 425 | Ritter Properties, LTD. | Fredericksbrg, TX 78624 | Oil & Gas Operator | Apr 2024 |
| 426 | Ritter, Laber & Associates, Inc. | Williston, ND 58802 | Oil & Gas Operator | Jan 2024 |
| 427 | River Bend Oil Company, Inc. | Crane, TX 79731 | Oil Operator | Jun 2013 |
| 428 | River City Resources, Inc. | Tulsa, OK 74119 | Oil & Gas Operator | Nov 1997 |
| 429 | Rivercity Operating, Inc. | Austin, TX 78766 | Oil & Gas Operator | Apr 2024 |
| 430 | Riverine, L.C. | Kilgore, TX 75663 | Oil & Gas Operator | Nov 2021 |
| 431 | Rivershore Operating LLC | Dallas, TX 75206 | Oil & Gas Operator | Apr 2024 |
| 432 | Riverstone Energy Operating, LLC | Houston, TX 77090 | Oil & Gas Operator | Apr 2024 |
| 433 | Riviera Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Feb 2024 |
| 434 | RJD Management Co., Inc. | Lubbock, TX 79408 | Oil & Gas Operator | Apr 2024 |
| 435 | RJKB Foster Operating LLC | New Braunfels, TX 78132 | Oil & Gas Operator | Apr 2024 |
| 436 | RJM Oil Company, LLC | Irving, TX 75060 | Oil Operator | Apr 2024 |
| 437 | RK Oil Production | Post, TX 79356 | Oil & Gas Operator | Jun 2023 |
| 438 | Rki Energy Resources, LLC | Oklahoma City, OK 73102 | Oil & Gas Operator | Jun 2021 |
| 439 | Rki Exploration & Production LLC | Tulsa, OK 74172 | Oil & Gas Operator | Apr 2024 |
| 440 | RKK Production Company | Mustang, OK 73064 | Oil & Gas Operator | Feb 2024 |
| 441 | RKW Operating LLC | Weatherford, TX 76085 | Gas Operator | Apr 2024 |
| 442 | RLB Enterprises, Inc. | Strawn, TX 76475 | Oil & Gas Operator | Feb 1997 |
| 443 | RLM Energy Company Inc. | Monroe, LA 71201 | Oil & Gas Operator | Mar 2008 |
| 444 | RLS Oil Company | Tulia, TX 79088 | Oil & Gas Operator | Apr 2024 |
| 445 | Rlu Oil & Gas, Inc. | Devine, TX 78016 | Oil & Gas Operator | Apr 2024 |
| 446 | Rlu Operating, LLC | Devine, TX 78016 | Oil & Gas Operator | Apr 2024 |
| 447 | RMB Operating LLC | Houston, TX 77269 | Oil & Gas Operator | Apr 2024 |
| 448 | RMC Petroleum, Inc. | Midland, TX 79710 | Oil & Gas Operator | Dec 1996 |
| 449 | Rme Austin Chalk Company | Houston, TX 77251 | Oil & Gas Operator | Nov 2002 |
| 450 | Rme Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Nov 2016 |
| 451 | Rmor Production | Kilgore, TX 75662 | Oil Operator | Apr 2024 |
| 452 | RMR Oil Company | Jacksboro, TX 76458 | Oil & Gas Operator | Sep 2005 |
| 453 | RMR Operating, LLC | Dallas, TX 75235 | Oil & Gas Operator | Apr 2024 |
| 454 | RMS Monte Christo, LLC | Snowmass VLG., CO 81615 | Oil & Gas Operator | Mar 2023 |
| 455 | RNS Oil Co. | Rio Grande Ci, TX 78582 | Oil Operator | Apr 2024 |
| 456 | Ro-Jo, Inc. | Highland VLG, TX 75077 | Oil & Gas Operator | Aug 2003 |
| 457 | Roach, R. Byron Trustee | Judson, TX 75660 | Oil & Gas Operator | Mar 1999 |
| 458 | Roach, R. Byron, Trustee, LLC | Judson, TX 75660 | Oil & Gas Operator | Mar 2007 |
| 459 | Road Oil Sales Inc. | Tyler, TX 75711 | Oil Operator | Dec 1984 |
| 460 | Roanoke Corporation | Fort Worth, TX 76102 | Oil & Gas Operator | Oct 1995 |
| 461 | Roaring Springs Energy, LTD. | Midland, TX 79702 | Oil & Gas Operator | Feb 2010 |
| 462 | Rob-Joe Gas & Oil Co. | Ranger, TX 76470 | Oil & Gas Operator | Apr 2024 |
| 463 | Robbins Petroleum Corp. | Longview, TX 75606 | Oil & Gas Operator | Sep 1994 |
| 464 | Robbins, L. C. | Seguin, TX 78155 | Oil & Gas Operator | Aug 2003 |
| 465 | Robby Kohutek, Inc. | Ballinger, TX 76821 | Oil & Gas Operator | Apr 2024 |
| 466 | Roberson Oil Company | Houston, TX 77046 | Oil & Gas Operator | Jan 2024 |
| 467 | Roberson, Joe | Vernon, TX 76385 | Oil & Gas Operator | Feb 2015 |
| 468 | Robert C. Brower, LLC | Southlake, TX 76092 | Oil & Gas Operator | Apr 2024 |
| 469 | Robert T. Epperson Prod Co, LLC | Tyler, TX 75713 | Gas Operator | Dec 2017 |
| 470 | Roberts & Hammack, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Apr 2024 |
| 471 | Roberts & Murphy, Inc. | Shreveport, LA 71137 | Oil & Gas Operator | Apr 2016 |
| 472 | Roberts & Roberts Enterprise,Inc | Levelland, TX 79336 | Oil & Gas Operator | Jun 1996 |
| 473 | Robertson Resources, Inc. | Midland, TX 79708 | Oil & Gas Operator | Apr 2024 |
| 474 | Robertson, French M. Oil Co. | Abilene, TX 79608 | Oil & Gas Operator | Mar 1995 |
| 475 | Robertson, Gene Oil Co. | Burkburnett, TX 76354 | Oil & Gas Operator | Jul 1998 |
| 476 | Robertson, T. L. Operating Co. | Cross Plains, TX 76443 | Oil & Gas Operator | May 2004 |
| 477 | Robertson-Bryce Management, LLC | Tyler, TX 75701 | Oil & Gas Operator | Apr 2024 |
| 478 | Robin Of Perryton Corporation | Perryton, TX 79070 | Oil & Gas Operator | Apr 2024 |
| 479 | Robin Of Perryton, Inc. | Perryton, TX 79070 | Oil & Gas Operator | Dec 1995 |
| 480 | Robin, Jack, Co. | Corpus Chrsti, TX 78410 | Oil & Gas Operator | Dec 2017 |
| 481 | Robinett Resources Inc. | Longview, TX 75601 | Oil & Gas Operator | Dec 1999 |
| 482 | Robinson Drilling Of Texas | Big Spring, TX 79721 | Oil & Gas Operator | Oct 1996 |
| 483 | Robinson Oil & Gas, Inc. | Chico, TX 76431 | Oil & Gas Operator | Aug 2003 |
| 484 | Robinson Oil Co. | Graham, TX 76450 | Oil & Gas Operator | Apr 2024 |
| 485 | Robinson Operating Company | Abilene, TX 79604 | Oil & Gas Operator | Aug 2012 |
| 486 | Robinson, Irvin | Abilene, TX 79608 | Oil & Gas Operator | May 1999 |
| 487 | Robuck Petroleum, LLC | Nacogdoches, TX 75965 | Oil & Gas Operator | Apr 2024 |
| 488 | Roc Energy, Inc. | Midland, TX 79710 | Oil & Gas Operator | Feb 2013 |
| 489 | Roc Operating, Inc. | Plano, TX 75093 | Oil & Gas Operator | Oct 2008 |
| 490 | Roca Operating, Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 2024 |
| 491 | Roca Production, Inc. | Fort Worth, TX 76107 | Oil & Gas Operator | Apr 2024 |
| 492 | Roca Resource Company, Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 493 | Rocanville Corporation | Dallas, TX 75225 | Oil & Gas Operator | Dec 2016 |
| 494 | Rocc Oil & Gas, L.P. | Houston, TX 77084 | Oil & Gas Operator | Apr 2024 |
| 495 | Rocc Operating, LLC | Houston, TX 77084 | Oil & Gas Operator | Apr 2024 |
| 496 | Rocinante | Houston, TX 77058 | Oil Operator | Apr 2024 |
| 497 | Rock Bottom Oil, GP, L.L.C. | Austin, TX 78747 | Oil & Gas Operator | Apr 2024 |
| 498 | Rock Creek Oil Co. | Iowa Park, TX 76367 | Oil Operator | Mar 2008 |
| 499 | Rock Creek Oil, Inc. | Dallas, TX 75225 | Oil & Gas Operator | Nov 2019 |
| 500 | Rock Energy Resources, LLC | Dallas, TX 75251 | Oil Operator | Apr 2024 |