| 401 | Oklahoma Oil & Gas MGMT Inc | Edmond, OK 73083-6786 | Oil & Gas Operator | Jan 2025 |
| 402 | Oklahoma Oil Tactics Inc | Edmond, OK 73003-1351 | Oil & Gas Operator | Mar 2015 |
| 403 | Okland Oil Company | Oklahoma City, OK 73102-9022 | Oil & Gas Operator | Feb 2025 |
| 404 | Oneok Exploration Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 405 | Oneok Field Services Company | Tulsa, OK 74103 | Oil & Gas Operator | Jul 2022 |
| 406 | Oneok Resources Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 407 | Onshore Royalties LLC | Houston, TX 77269 | Oil & Gas Operator | Feb 2025 |
| 408 | Orca Operating Company LLC | Houston, TX 77056 | Oil & Gas Operator | Feb 2025 |
| 409 | Oryx Crude Trading & Transporation LP | Dallas, TX 75221 | Oil & Gas Operator | Jun 1999 |
| 410 | Otc Petroleum Corporation | Nichols Hill, OK 73116 | Oil & Gas Operator | Mar 2015 |
| 411 | Ovintiv Mid-Continent Inc. | The Woodlands, TX 77380-2764 | Oil & Gas Operator | Feb 2025 |
| 412 | Oxley Petroleum Co | Oklahoma City, OK 73118-1044 | Oil & Gas Operator | Sep 2017 |
| 413 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Apr 2025 |
| 414 | P & P Producing Inc | Midland, TX 79702 | Oil & Gas Operator | Feb 2015 |
| 415 | P.O.&G. Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Apr 2025 |
| 416 | Panhandle Oil & Gas Consultants Inc | Woodward, OK 73802-5011 | Oil & Gas Operator | Jul 2015 |
| 417 | Panhandle Trading Company | Houston, TX 77251-1642 | Oil & Gas Operator | Jun 2003 |
| 418 | Pantera Energy Company | Amarillo, TX 79101 | Oil & Gas Operator | Apr 2025 |
| 419 | Pardee Production Co. | Skiatook, OK 74070 | Oil & Gas Operator | Mar 2021 |
| 420 | Parker & Parsley Dev Co | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 421 | Parker & Parsley Dev LP | Irving, TX 75039-3745 | Oil & Gas Operator | Mar 2015 |
| 422 | Patron Energy LLC | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2015 |
| 423 | Payne W C Family Trust | Oklahoma City, OK 73116-9044 | Oil & Gas Operator | Mar 2015 |
| 424 | Peak Operating Oil & Gas LLC | Wichita, KS 67226-3375 | Oil & Gas Operator | Jan 2025 |
| 425 | Pennzoil Petroleum Company | Houston, TX 77252 | Oil & Gas Operator | Nov 1999 |
| 426 | Pet-Ex, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2024 |
| 427 | Petra Petroleum Inc | Littleton, CO 80160-0319 | Oil & Gas Operator | Jun 2005 |
| 428 | Petro Speed Inc | Norman, OK 73069-8116 | Oil & Gas Operator | Mar 2015 |
| 429 | Petroleum Development Company | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2025 |
| 430 | Petroleum Inc | Wichita, KS 67202 | Oil & Gas Operator | Oct 2021 |
| 431 | Pioneer Natural Res. USA, Inc. | Irving, TX 75038 | Oil & Gas Operator | Apr 2025 |
| 432 | Plains Marketing LP | Cushing, OK 74023 | Oil & Gas Operator | Dec 2022 |
| 433 | Polaris Energy Dev Co | Tulsa, OK 74135 | Oil & Gas Operator | Apr 2000 |
| 434 | Powerline Energy Corporation | Arlington, TX 76015 | Oil & Gas Operator | Apr 2025 |
| 435 | Premier Resources LTD | Denver, CO 80237 | Oil & Gas Operator | Jul 2002 |
| 436 | Prentice Napier & Green Inc | Oklahoma City, OK 73142 | Oil & Gas Operator | Feb 2025 |
| 437 | Presidio Petroleum LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2025 |
| 438 | Pride Energy Company | Tulsa, OK 74170 | Oil & Gas Operator | Apr 2025 |
| 439 | Primary Natural Resources III LLC | Tulsa, OK 74136-6351 | Oil & Gas Operator | Feb 2025 |
| 440 | Primary Natural Resources Inc. | Tulsa, OK 74136-6351 | Oil & Gas Operator | Mar 2023 |
| 441 | Prime Energy Corp | Charleston, WV 25301-1707-1707 | Oil & Gas Operator | Sep 2015 |
| 442 | Prime Operating Company | Houston, TX 77024 | Oil & Gas Operator | Apr 2025 |
| 443 | Prize Operating Company | Grapevine, TX 76051 | Oil & Gas Operator | Aug 2016 |
| 444 | Proex Energy Management, L.L.C. | Spring, TX 77386 | Oil & Gas Operator | Apr 2025 |
| 445 | Prospective Investment & Trading | Scottsdale, AZ 85261-4190 | Oil & Gas Operator | Jun 2016 |
| 446 | Protege Energy LLC | Tulsa, OK 74135 | Oil & Gas Operator | Jan 2018 |
| 447 | Providence Energy Corporation | Broken Arrow, OK 74013-3783 | Oil & Gas Operator | Feb 1994 |
| 448 | Providence Oil & Gas Corp | Tulsa, OK 74135-5463 | Oil & Gas Operator | May 2005 |
| 449 | Pruitt Operating Company LLC | Ratliff City, OK 73481-5802 | Oil & Gas Operator | Feb 2025 |
| 450 | Qep Energy Company | Midland, TX 79701 | Oil & Gas Operator | Jan 2025 |
| 451 | Quail Oil & Gas LC | Garden City, KS 67846 | Oil & Gas Operator | Jan 2025 |
| 452 | Quantum Resources Management LLC | Houston, TX 77010 | Oil & Gas Operator | Jan 2025 |
| 453 | Questa Energy Corporation | Amarillo, TX 79159 | Oil & Gas Operator | Apr 2025 |
| 454 | Questa Oil & Gas Co. | Tulsa, OK 74170 | Oil & Gas Operator | Mar 2015 |
| 455 | Questar Energy Trading | Salt Lake City, UT 84145-0601 | Oil & Gas Operator | Mar 2020 |
| 456 | Questar Explor & Prod Co | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2017 |
| 457 | R & A Moore, Inc. | Cleburne, TX 76033 | Oil & Gas Operator | Apr 2025 |
| 458 | R C Taylor Operating Company LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Mar 2025 |
| 459 | R M S Oil & Gas | Amarillo, TX 79101-2445 | Oil & Gas Operator | Sep 1997 |
| 460 | Ra-Jac LLC | Norman, OK 73072 | Oil & Gas Operator | Feb 2025 |
| 461 | Raker Resources LLC | Houston, TX 77042 | Oil & Gas Operator | Apr 2025 |
| 462 | Ramco Oil & Gas Inc | Midland, TX 79701 | Oil & Gas Operator | Nov 2006 |
| 463 | Range Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2021 |
| 464 | Rasmussen, Hal J. Operating, Inc | Midland, TX 79701 | Oil & Gas Operator | Apr 2009 |
| 465 | Raydon Exploration, Inc. | Oklahoma City, OK 73118 | Oil & Gas Operator | Apr 2025 |
| 466 | RB Operating Company | Shawnee, OK 74802-1488 | Oil & Gas Operator | Apr 2015 |
| 467 | Reading & Bates Petroleum Co | Tulsa, OK 74136 | Oil & Gas Operator | Aug 2009 |
| 468 | Red Rock Resources, L.L.C. | Wichita Falls, TX 76310 | Oil & Gas Operator | Jan 2025 |
| 469 | Redland Resources, LLC | Oklahoma City, OK 73127 | Oil & Gas Operator | Feb 2025 |
| 470 | Redline Energy LLC | Dover, OK 73734 | Oil & Gas Operator | Feb 2025 |
| 471 | Redstone Oil & Gas Company | Dallas, TX 75225 | Oil & Gas Operator | Jan 2020 |
| 472 | Regency Exploration Inc | Oklahoma City, OK 73102-5605 | Oil & Gas Operator | Mar 1999 |
| 473 | Resources Investment Corp | Denver, CO 80202 | Oil & Gas Operator | Sep 2018 |
| 474 | Revelation Resources | Cypress, TX 77410-2578 | Oil & Gas Operator | Jan 2025 |
| 475 | Richard W Thompson Inc | Plano, TX 75075 | Oil & Gas Operator | Jul 2019 |
| 476 | Richardson WM S | Duncan, OK 73533 | Oil Operator | Jun 2013 |
| 477 | Ricks Exploration Co | Oklahoma City, OK 73112 | Oil & Gas Operator | Mar 2015 |
| 478 | Riviera Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Feb 2025 |
| 479 | RKK Production Company | Mustang, OK 73064 | Oil & Gas Operator | Feb 2025 |
| 480 | RL&B Energy LLC | Wichita Falls, TX 76230 | Oil & Gas Operator | Jan 2025 |
| 481 | Roberts & Murphy, Inc. | Shreveport, LA 71137 | Oil & Gas Operator | Apr 2016 |
| 482 | Rosewood Resources, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Apr 2025 |
| 483 | Royalty Energy Development LLC | Edmond, OK 73003 | Oil & Gas Operator | Feb 2025 |
| 484 | RTC Resources, LLP | Weatherford, OK 73096 | Oil & Gas Operator | Apr 2025 |
| 485 | Russell D Meloy Oil & Gas Co | Enid, OK 73703-1623 | Oil & Gas Operator | Jan 2025 |
| 486 | Ryan Petroleum Corp | Oklahoma City, OK 73102-9024 | Oil & Gas Operator | Aug 1994 |
| 487 | S A C Operating Inc | Woodward, OK 73802-1749 | Oil & Gas Operator | Jan 1999 |
| 488 | Sabre Operating, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Apr 2025 |
| 489 | Samson Exploration LLC | Tulsa, OK 74101 | Oil & Gas Operator | Feb 2025 |
| 490 | Samson Gas Producing Company | Tulsa, OK 74103 | Oil & Gas Operator | May 2001 |
| 491 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 492 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2025 |
| 493 | Sandridge Energy, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | May 2018 |
| 494 | Sandridge Exploration And Production LLC | Oklahoma City, OK 73104 | Oil & Gas Operator | Apr 2025 |
| 495 | Savoy Energy LP | Traverse City, MI 49685-1560-1560 | Oil & Gas Operator | Feb 2025 |
| 496 | Schmid Properties Inc | Hico, TX 76457 | Oil & Gas Operator | Apr 2025 |
| 497 | Seabren Gas System Inc | Okla City, OK 73112 | Oil & Gas Operator | Mar 2016 |
| 498 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 499 | Seagull Midcon Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 500 | Seaport Inc | Oklahoma City, OK 73131 | Oil & Gas Operator | Jan 2025 |