| 401 | Mustang Fuel Corporation | Oklahoma City, OK 73114 | Oil & Gas Operator | Feb 2024 |
| 402 | Nadel And Gussman, L.L.C. | Tulsa, OK 74103 | Oil & Gas Operator | May 2024 |
| 403 | Nard Inc | Buffalo, OK 73834-9737 | Oil Operator | Dec 2005 |
| 404 | National Cooperative RFG Assoc | McPherson, KS 67460-1404 | Oil & Gas Operator | Jun 2006 |
| 405 | National Oil Company | Garden City, KS 67846 | Oil & Gas Operator | Jan 2024 |
| 406 | Natural Gas Anadarko Company | Perryton, TX 79070 | Oil & Gas Operator | May 2024 |
| 407 | Natural Gas Compression Corp | Cleveland, OK 74020-0065 | Oil & Gas Operator | Nov 2023 |
| 408 | Natural Gas Pipeline Co Of Am LLC | Downers Grove, IL 60515-3708 | Oil & Gas Operator | Mar 2015 |
| 409 | Nelson Exploration Corporation | | Oil & Gas Operator | Jan 2024 |
| 410 | Nemaha Environmental Services LLC | Enid, OK 73703 | Oil Operator | Feb 2024 |
| 411 | Noble Energy Inc | Midland, TX 79706 | Oil & Gas Operator | May 2024 |
| 412 | Northwest Disposal Corporation | Laverne, OK 73848-0504 | Oil & Gas Operator | Jul 2014 |
| 413 | O G & E | Oklahoma City, OK 73124-0300 | Oil & Gas Operator | Feb 2014 |
| 414 | O K Swabbing Inc | Hennessey, OK 73742-0835 | Oil & Gas Operator | Jan 2024 |
| 415 | O'Brien Energy Resources Corp | Portsmouth, NH 03801 | Oil & Gas Operator | May 2024 |
| 416 | O'Neill Properties, LTD. | Midland, TX 79702 | Oil & Gas Operator | May 2024 |
| 417 | Oexco, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2015 |
| 418 | Oil Producers, Inc. Of Kansas | Wichita, KS 67206 | Oil & Gas Operator | May 2024 |
| 419 | Okie Crude Company | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2024 |
| 420 | Oklahoma Liquid Resources Inc | Owasso, OK 74055-0841 | Oil & Gas Operator | Jan 2024 |
| 421 | Oklahoma Oil & Gas MGMT Inc | | Oil & Gas Operator | Jan 2024 |
| 422 | Oklahoma Oil Tactics Inc | Edmond, OK 73003-1351 | Oil & Gas Operator | Mar 2015 |
| 423 | Oklahoma Petroleum Allies LLC | Ardmore, OK 73401 | Oil Operator | Oct 2023 |
| 424 | Okland Oil Company | Oklahoma City, OK 73102-9022 | Oil & Gas Operator | Feb 2024 |
| 425 | Oneok Exploration Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 426 | Oneok Field Services Company | Tulsa, OK 74103 | Oil & Gas Operator | Jul 2022 |
| 427 | Oneok Resources Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 428 | Onshore Royalties LLC | Houston, TX 77269 | Oil & Gas Operator | Feb 2024 |
| 429 | Orca Operating Company LLC | Houston, TX 77056 | Oil & Gas Operator | Feb 2024 |
| 430 | Oryx Crude Trading & Transporation LP | Dallas, TX 75221 | Oil & Gas Operator | Jun 1999 |
| 431 | Otc Petroleum Corporation | Oklahoma City, OK 73116 | Oil & Gas Operator | Mar 2015 |
| 432 | Ovintiv Mid-Continent Inc. | The Woodlands, TX 77380-2764 | Oil & Gas Operator | Jan 2024 |
| 433 | Oxley Petroleum Co | Oklahoma City, OK 73118-1044 | Oil & Gas Operator | Sep 2017 |
| 434 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | May 2024 |
| 435 | P & P Producing Inc | Midland, TX 79702 | Oil & Gas Operator | Feb 2015 |
| 436 | P O & G Operating LLC | Houston, TX 77057 | Oil & Gas Operator | May 2024 |
| 437 | Panhandle Oil & Gas Consultants Inc | Woodward, OK 73802-5011 | Oil & Gas Operator | Jul 2015 |
| 438 | Panhandle Trading Company | Houston, TX 77251-1642 | Oil & Gas Operator | Jun 2003 |
| 439 | Pantera Energy Company | Amarillo, TX 79101 | Oil & Gas Operator | May 2024 |
| 440 | Paramount Petroleum Corp | Dallas, TX 75374 | Oil Operator | Dec 2000 |
| 441 | Pardee Production Co. | Skiatook, OK 74070 | Oil & Gas Operator | Mar 2021 |
| 442 | Parker & Parsley Dev Co | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 443 | Parker & Parsley Dev LP | Irving, TX 75039-3745 | Oil & Gas Operator | Mar 2015 |
| 444 | Patron Energy LLC | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2015 |
| 445 | Payne W C Family Trust | Oklahoma City, OK 73116-9044 | Oil & Gas Operator | Mar 2015 |
| 446 | PBT Enterprises Inc | Garber, OK 73738-0262 | Oil & Gas Operator | May 2023 |
| 447 | Peak Operating Oil & Gas LLC | | Oil & Gas Operator | Jan 2024 |
| 448 | Pennzoil Petroleum Company | Houston, TX 77252 | Oil & Gas Operator | Nov 1999 |
| 449 | Pet-Ex, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jan 2024 |
| 450 | Petra Petroleum Inc | Littleton, CO 80160-0319 | Oil & Gas Operator | Jun 2005 |
| 451 | Petro Speed Inc | Norman, OK 73069-8116 | Oil & Gas Operator | Mar 2015 |
| 452 | Petroleum Development Company | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2024 |
| 453 | Petroleum Inc | Wichita, KS 67202 | Oil & Gas Operator | Oct 2021 |
| 454 | Pioneer Natural Res. USA, Inc. | Irving, TX 75038 | Oil & Gas Operator | May 2024 |
| 455 | Plains Marketing LP | Cushing, OK 74023 | Oil & Gas Operator | Dec 2022 |
| 456 | Polaris Energy Dev Co | Tulsa, OK 74135 | Oil & Gas Operator | Apr 2000 |
| 457 | Powerline Energy Corporation | Arlington, TX 76015 | Oil & Gas Operator | May 2024 |
| 458 | Premier Resources LTD | Denver, CO 80237 | Oil & Gas Operator | Jul 2002 |
| 459 | Prentice Napier & Green Inc | Oklahoma City, OK 73172-1424 | Oil & Gas Operator | Feb 2024 |
| 460 | Presidio Petroleum LLC | Fort Worth, TX 76102 | Oil & Gas Operator | May 2024 |
| 461 | Pride Energy Company | Tulsa, OK 74170 | Oil & Gas Operator | May 2024 |
| 462 | Primary Natural Resources III LLC | Tulsa, OK 74136-6351 | Oil & Gas Operator | Feb 2024 |
| 463 | Primary Natural Resources Inc. | Tulsa, OK 74136-6351 | Oil & Gas Operator | Mar 2023 |
| 464 | Prime Energy Corp | Charleston, WV 25301-1707-1707 | Oil & Gas Operator | Sep 2015 |
| 465 | Prime Operating Company | Houston, TX 77024 | Oil & Gas Operator | May 2024 |
| 466 | Prize Operating Company | Grapevine, TX 76051 | Oil & Gas Operator | Aug 2016 |
| 467 | Proex Energy Management, L.L.C. | Spring, TX 77386 | Oil & Gas Operator | May 2024 |
| 468 | Prospective Investment & Trading | Scottsdale, AZ 85261-4190 | Oil & Gas Operator | Jun 2016 |
| 469 | Protege Energy LLC | Tulsa, OK 74135 | Oil & Gas Operator | Jan 2018 |
| 470 | Proven Reserves Management, Inc. | Dallas, TX 75370 | Oil & Gas Operator | Jan 2024 |
| 471 | Providence Energy Corporation | Broken Arrow, OK 74013-3783 | Oil & Gas Operator | Feb 1994 |
| 472 | Providence Oil & Gas Corp | Tulsa, OK 74135-5463 | Oil & Gas Operator | May 2005 |
| 473 | Pruitt Operating Company LLC | Ratliff City, OK 73481-5802 | Oil & Gas Operator | Feb 2024 |
| 474 | Qep Energy Company | Midland, TX 79701 | Oil & Gas Operator | Jan 2024 |
| 475 | Quail Oil & Gas LC | Garden City, KS 67846 | Oil & Gas Operator | Jan 2024 |
| 476 | Quantum Resources Management LLC | Houston, TX 77010 | Oil & Gas Operator | Jan 2024 |
| 477 | Questa Energy Corporation | Amarillo, TX 79159 | Oil & Gas Operator | May 2024 |
| 478 | Questa Oil & Gas Co. | Tulsa, OK 74170 | Oil & Gas Operator | Mar 2015 |
| 479 | Questar Energy Trading | Salt Lake City, UT 84145-0601 | Oil & Gas Operator | Mar 2020 |
| 480 | Questar Explor & Prod Co | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2017 |
| 481 | R & A Moore, Inc. | Cleburne, TX 76033 | Oil & Gas Operator | May 2024 |
| 482 | R C Taylor Operating Company LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Feb 2024 |
| 483 | Ra-Jac LLC | Norman, OK 73070-4656 | Oil & Gas Operator | Feb 2024 |
| 484 | Raker Resources LLC | Houston, TX 77042 | Oil & Gas Operator | May 2024 |
| 485 | Ramco Oil & Gas Inc | Midland, TX 79701 | Oil & Gas Operator | Nov 2006 |
| 486 | Range Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2021 |
| 487 | Rasmussen, Hal J. Operating, Inc | Midland, TX 79701 | Oil & Gas Operator | Apr 2009 |
| 488 | Raydon Exploration, Inc. | Oklahoma City, OK 73118 | Oil & Gas Operator | May 2024 |
| 489 | RB Operating Company | Shawnee, OK 74802-1488 | Oil & Gas Operator | Apr 2015 |
| 490 | Reading & Bates Petroleum Co | Tulsa, OK 74136 | Oil & Gas Operator | Aug 2009 |
| 491 | Red Hawk Disposal LLC | | Oil Operator | Jun 2023 |
| 492 | Red Rock Resources, L.L.C. | Wichita Falls, TX 76310 | Oil & Gas Operator | Jan 2024 |
| 493 | Redland Resources, LLC | Oklahoma City, OK 73127 | Oil & Gas Operator | Feb 2024 |
| 494 | Redline Energy LLC | | Oil & Gas Operator | Feb 2024 |
| 495 | Redstone Oil & Gas Company | Dallas, TX 75225 | Oil & Gas Operator | Jan 2020 |
| 496 | Regency Exploration Inc | Oklahoma City, OK 73102-5605 | Oil & Gas Operator | Mar 1999 |
| 497 | Resources Investment Corp | Denver, CO 80202 | Oil & Gas Operator | May 2023 |
| 498 | Revelation Resources | Cypress, TX 77410-2578 | Oil & Gas Operator | Jan 2024 |
| 499 | Richard W Thompson Inc | Plano, TX 75026 | Oil & Gas Operator | Jul 2019 |
| 500 | Richardson WM S | Duncan, OK 73533 | Oil Operator | Jun 2013 |