| 301 | Noco Investment Company Inc | Tulsa, OK 74159-0470 | Oil & Gas Operator | Mar 2005 |
| 302 | Nogp Operating Company Inc | Tomball, TX 77377 | Oil & Gas Operator | Jan 2026 |
| 303 | Northwest Disposal Corporation | Laverne, OK 73848-0504 | Oil & Gas Operator | Jul 2014 |
| 304 | Nub'S Well Servicing Inc | Ratliff City, OK 73481 | Oil & Gas Operator | Feb 2026 |
| 305 | NWM Properties LLC | Tulsa, OK 74131-4426 | Oil Operator | Feb 2026 |
| 306 | Octagon Resources LLC | Norman, OK 73071-1295 | Oil & Gas Operator | May 2015 |
| 307 | Oil & Gas Exploration Inc | Cleveland, OK 74020 | Oil & Gas Operator | Aug 2013 |
| 308 | Oil State Petroleum Inc | Jennings, OK 74038 | Oil & Gas Operator | Feb 2026 |
| 309 | Oilfield Operating Company | Cushing, OK 74023-1347 | Oil & Gas Operator | Jan 2018 |
| 310 | Oilton Petroleum Inc | Oilton, OK 74052-0459 | Oil & Gas Operator | Oct 2001 |
| 311 | Okie Crude Company | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2026 |
| 312 | Oklahoma Cellulose Inc | Cleveland, OK 74020 | Oil Operator | Feb 2026 |
| 313 | Oklahoma Liquid Resources Inc | Collinsville, OK 74021 | Oil & Gas Operator | Dec 2025 |
| 314 | Oklahoma Oil & Gas MGMT Inc | Edmond, OK 73083-6786 | Oil & Gas Operator | Jan 2026 |
| 315 | Okt Petroleum Company Inc | Oklahoma City, OK 73118-7425 | Oil & Gas Operator | Oct 2013 |
| 316 | Osage Oil & Transportation Inc | Cleveland, OK 74020 | Oil & Gas Operator | Nov 2000 |
| 317 | Osburn Gerald Dba Ozzy & Son Oil & Gas | Drumright, OK 74030-5467 | Oil Operator | Oct 2020 |
| 318 | Osterhout Phillip L | Drumright, OK 74030-0693 | Oil & Gas Operator | Jan 2014 |
| 319 | Oxford Oil Inc | Cleveland, OK 74020 | Oil & Gas Operator | Feb 1997 |
| 320 | Pablo Energy II, LLC | Amarillo, TX 79105 | Oil & Gas Operator | Jan 2026 |
| 321 | Pace Exploration LLC | Tulsa, OK 74133 | Oil & Gas Operator | Nov 2025 |
| 322 | Pan Western Energy Corporation | Tulsa, OK 74114 | Oil & Gas Operator | Apr 2026 |
| 323 | Paradigm Twenty LLC | Stillwater, OK 74074-1745 | Oil & Gas Operator | Jan 2026 |
| 324 | Paramount Petroleum Corp | Dallas, TX 75374 | Oil Operator | Dec 2000 |
| 325 | Parker & Parsley Dev Co | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 326 | Parwest Land Exploration Inc | Oklahoma City, OK 73112 | Oil & Gas Operator | Jan 2026 |
| 327 | Patina Oil & Gas Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2016 |
| 328 | Patina Oklahoma Corp | Duncan, OK 73533-9523 | Oil & Gas Operator | Nov 2014 |
| 329 | Patriot Petroleum Co LLC | Coppell, TX 75019-4216 | Oil & Gas Operator | Jan 2013 |
| 330 | Pawnee Petroleum Company | Seminole, OK 74868-0951 | Oil & Gas Operator | Feb 2023 |
| 331 | Payneco Pipeline Company | Yale, OK 74085 | Oil & Gas Operator | Dec 2000 |
| 332 | Paystone Oil Corporation | Tulsa, OK 74105 | Oil Operator | Mar 2009 |
| 333 | Pease George W Jr | Fairfax, OK 74637 | Oil & Gas Operator | Mar 1998 |
| 334 | Pelto Oil Company | Houston, TX 77002 | Oil & Gas Operator | Nov 1998 |
| 335 | Penn Production Company Inc | | Oil & Gas Operator | Nov 2014 |
| 336 | Perkins Energy Company | Duncan, OK 73533-3853 | Oil & Gas Operator | Feb 2026 |
| 337 | Petro Warrior LLC | Wichita, KS 67206 | Oil & Gas Operator | Jan 2026 |
| 338 | Petroleum Resources Co | Wichita, KS 67206 | Oil & Gas Operator | May 2000 |
| 339 | Petron Energy Inc | Dallas, TX 75252 | Oil & Gas Operator | Apr 2026 |
| 340 | Petroquest Energy, L.L.C. | Lafayette, LA 70505 | Oil & Gas Operator | Apr 2026 |
| 341 | Phillips Oil Operating Co | Enid, OK 73703-4921 | Oil & Gas Operator | May 2019 |
| 342 | Phillips, Warren P | | Oil & Gas Operator | Apr 2011 |
| 343 | Pinnacle Corporation (The) | Broken Arrow, OK 74012 | Oil & Gas Operator | Nov 2014 |
| 344 | Pinnacle Operating Company LLC | Tulsa, OK 74137 | Oil & Gas Operator | Feb 2026 |
| 345 | Pitco Production Company | Tulsa, OK 74170-2320 | Oil & Gas Operator | May 2013 |
| 346 | Plumb Resources, Inc. | Houston, TX 77096 | Oil & Gas Operator | Jun 1998 |
| 347 | Pogue Randall | Ada, OK 74821-1547 | Oil & Gas Operator | Apr 2014 |
| 348 | Polaris Petroleum Operations LLC | Branson West, MO 65737 | Oil & Gas Operator | May 2019 |
| 349 | Pollard Jr G W | Okmulgee, OK 74447 | Oil & Gas Operator | Apr 2015 |
| 350 | Post Oak Oil Company | Oklahoma City, OK 73112 | Oil & Gas Operator | Jul 2013 |
| 351 | Powell James S | Cleveland, OK 74020 | Oil Operator | Feb 2026 |
| 352 | Premier Gas Company LLC | Durant, OK 74701 | Oil Operator | Dec 2025 |
| 353 | Presley Petroleum Company | Newport Beach, CA 92658-2200 | Oil & Gas Operator | Oct 1999 |
| 354 | Pri Producing Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2006 |
| 355 | Producers Oil Company | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2007 |
| 356 | Pulliam Dennis L | Mannford, OK 74044-9733 | Oil & Gas Operator | Nov 2001 |
| 357 | Pulliam Melvin | Mannford, OK 74044 | Oil & Gas Operator | Jul 2019 |
| 358 | R & D Oil & Gas | Exeter, CA 93221-9697 | Oil & Gas Operator | Aug 2019 |
| 359 | R & N Oil Company | Fairfax, OK 74637 | Oil & Gas Operator | May 2013 |
| 360 | R D T Properties | Tulsa, OK 74105-7122 | Oil & Gas Operator | Sep 2017 |
| 361 | R K R Exploration | Seminole, OK 74868-9754 | Oil & Gas Operator | Mar 2015 |
| 362 | R.E.J.A.S. Energy LLC | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2026 |
| 363 | Ramco Oil Company | Pawhuska, OK 74056 | Oil & Gas Operator | Feb 2012 |
| 364 | Ramsey Property Management LLC | Oklahoma City, OK 73120 | Oil & Gas Operator | Jan 2026 |
| 365 | Raper Brice Oil Company LLC | Yale, OK 74085-6865 | Oil & Gas Operator | Apr 2015 |
| 366 | Raydon Exploration, Inc. | Oklahoma City, OK 73118 | Oil & Gas Operator | Apr 2026 |
| 367 | Red Fork (USA) Investments Inc | Midland, TX 79710-0272 | Oil & Gas Operator | May 2019 |
| 368 | Red Fork Oil Production Inc | Mannford, OK 74044-0492 | Oil & Gas Operator | Feb 2017 |
| 369 | Red Tail Properties, LLC | Tulsa, OK 74107-3443 | Oil Operator | Jan 2026 |
| 370 | Remo Production Co | Stillwater, OK 74074-9333 | Oil Operator | Apr 2014 |
| 371 | Ric Petroleum, Inc. | Wichita Falls, TX 76307 | Oil & Gas Operator | Aug 2003 |
| 372 | RKR Exploration Inc | Seminole, OK 74868 | Oil & Gas Operator | Feb 2026 |
| 373 | Robbins Thomas D & Charlene A Revocable Trust | Plano, TX 75093-7471 | Oil Operator | Jul 2018 |
| 374 | Robinowitz Oil Company | Tulsa, OK 74136-1429 | Oil & Gas Operator | Feb 2023 |
| 375 | Rocky Top Energy LLC | Bartlesville, OK 74003 | Oil & Gas Operator | Sep 2025 |
| 376 | Roe Oil Company | Cushing, OK 74023-0086 | Oil & Gas Operator | Nov 2025 |
| 377 | Rogers County Coal Seam LLC | Ridgeland, MS 39157-8635 | Oil & Gas Operator | Mar 2015 |
| 378 | Rogers Jerry L | Cushing, OK 74023-0911 | Oil & Gas Operator | Mar 2017 |
| 379 | Rogers Well Service Inc | Ponca City, OK 74601 | Oil & Gas Operator | Apr 2014 |
| 380 | Roseland Oil & Gas Inc | Rockwall, TX 75087 | Oil & Gas Operator | Feb 2003 |
| 381 | Royal Oaks Petroleum Corp | Fort Worth, TX 76116 | Oil & Gas Operator | Dec 2001 |
| 382 | Royalty Energy Development LLC | Edmond, OK 73003 | Oil & Gas Operator | Feb 2026 |
| 383 | RTB Oil Inc | Crescent, OK 73028-0686 | Oil Operator | May 2016 |
| 384 | Ruh Oil Company | Collinsville, OK 74021 | Oil & Gas Operator | Jan 2026 |
| 385 | S & C Resources Inc | Cleveland, OK 74020 | Oil Operator | May 2025 |
| 386 | S & M Production Inc | Pawnee, OK 74058 | Oil & Gas Operator | Aug 2023 |
| 387 | Sabos George U | Tulsa, OK 74170 | Oil & Gas Operator | Jan 2013 |
| 388 | Sallee Oil Corporation | Collinsville, OK 74021 | Oil & Gas Operator | Feb 2026 |
| 389 | Sandia Operating Corp. | San Antonio, TX 78270 | Oil & Gas Operator | May 2010 |
| 390 | Scavenger Oil Company Inc | Englewood, CO 80111 | Oil & Gas Operator | Mar 2000 |
| 391 | Schuler Jr Chris C | Cleveland, OK 74020 | Oil Operator | Aug 2013 |
| 392 | Scissortail Energy LLC | Tulsa, OK 74137-3644 | Oil & Gas Operator | Jan 2026 |
| 393 | Senax Inc | Tulsa, OK 74105-2206 | Oil & Gas Operator | Feb 2026 |
| 394 | Service Drilling Co. | Tulsa, OK 74119 | Oil & Gas Operator | Oct 1998 |
| 395 | Service Drilling Co., L.L.C. | Tulsa, OK 74119 | Oil & Gas Operator | Oct 2003 |
| 396 | Seven J Oil Inc | Jenning, OK 74038-9729 | Oil & Gas Operator | Sep 2025 |
| 397 | Shallow Energy Inc | South Dennis, MA 2660 | Oil & Gas Operator | Feb 2025 |
| 398 | Shar Alan Oil Company | | Oil & Gas Operator | Oct 2005 |
| 399 | Sharber Billy Jack Operating | Konawa, OK 74849-0071 | Oil & Gas Operator | Mar 2015 |
| 400 | Shell Western Expl & Prod Inc | Houston, TX 77251 | Oil & Gas Operator | Mar 2015 |