| 301 | Pardee Production Co. | Skiatook, OK 74070 | Oil & Gas Operator | Mar 2021 |
| 302 | Parker & Parsley Development L.P | Midland, TX 79702 | Oil & Gas Operator | Oct 2007 |
| 303 | Patina Oil & Gas Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2016 |
| 304 | Payne, W. C. | Nichols Hill, OK 73116 | Oil & Gas Operator | Sep 2005 |
| 305 | Peak Operating Of Texas, LLC | Denver, CO 80202 | Oil & Gas Operator | May 2005 |
| 306 | Pegasus Energy | Oklahoma City, OK 73162 | Oil & Gas Operator | Apr 1997 |
| 307 | Pennzoil Exploration & Production Co. | Carthage, TX 75633 | Oil & Gas Operator | Mar 2008 |
| 308 | Pennzoil Petroleum Company | Houston, TX 77252 | Oil & Gas Operator | Nov 1999 |
| 309 | Penroc Oil Corp. | Hobbs, NM 88241 | Oil & Gas Operator | May 2025 |
| 310 | Petrohawk Operating Company | Houston, TX 77056 | Oil & Gas Operator | Oct 2021 |
| 311 | Petroleum Inc | Wichita, KS 67202 | Oil & Gas Operator | Oct 2021 |
| 312 | Philcon Development Co. | Amarillo, TX 79101 | Oil & Gas Operator | Sep 2014 |
| 313 | Phillips Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Mar 2013 |
| 314 | Pioneer Natural Res. USA, Inc. | Spring, TX 77389 | Oil & Gas Operator | Jul 2025 |
| 315 | Pitco Investments, LTD. | Scottsdale, AZ 85261 | Oil & Gas Operator | Jan 2013 |
| 316 | Plains Exploration & Prod. Co. | Houston, TX 77002 | Oil & Gas Operator | Jul 2013 |
| 317 | Plains Marketing, LP | Cushing, OK 74023 | Oil Operator | Jan 2012 |
| 318 | Plantation Operating, LLC | Houston, TX 77041 | Oil & Gas Operator | Nov 2011 |
| 319 | PN Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Aug 2003 |
| 320 | Pogo Producing Company | Houston, TX 77002 | Oil & Gas Operator | Jan 2008 |
| 321 | Post, George P. | Oklahoma City, OK 73118 | Oil & Gas Operator | Jul 2025 |
| 322 | Powerline Energy Corporation | Arlington, TX 76015 | Oil & Gas Operator | Jul 2025 |
| 323 | Presidio Petroleum LLC | Canadian, TX 79014 | Oil & Gas Operator | Jul 2025 |
| 324 | Pride Energy Company | Tulsa, OK 74170 | Oil & Gas Operator | Jul 2025 |
| 325 | Prize Operating Company | Grapevine, TX 76051 | Oil & Gas Operator | Aug 2016 |
| 326 | Protege Energy LLC | Tulsa, OK 74135 | Oil & Gas Operator | Jan 2018 |
| 327 | Qep Energy Company | Midland, TX 79701 | Oil & Gas Operator | Apr 2025 |
| 328 | Questa Energy Corporation | Amarillo, TX 79159 | Oil & Gas Operator | Jul 2025 |
| 329 | Questa Oil & Gas Co. | Tulsa, OK 74170 | Oil & Gas Operator | Mar 2015 |
| 330 | Questa Operating Company, LLC | Amarillo, TX 79159 | Oil & Gas Operator | Jul 2025 |
| 331 | Questar Expl. And Prod. Co. | Salt Lake Cty, UT 84145 | Oil & Gas Operator | Jul 2011 |
| 332 | R.E.D. Resources, Inc. | Perryton, TX 79070 | Oil & Gas Operator | Apr 2004 |
| 333 | Ram Operating Inc. | Browns, IL 62818 | Oil & Gas Operator | Aug 2008 |
| 334 | Ramco Oil & Gas Inc | Midland, TX 79701 | Oil & Gas Operator | Nov 2006 |
| 335 | Ramco Operating Company | Tulsa, OK 74135 | Oil & Gas Operator | Jan 1998 |
| 336 | Range Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2021 |
| 337 | Range Production Company, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2025 |
| 338 | Remora Operating LLC | Houston, TX 77056 | Oil & Gas Operator | Jul 2025 |
| 339 | Resource Oil And Gas, LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Jul 2025 |
| 340 | Revolution Operating Company,LLC | Oklahoma City, OK 73134 | Oil & Gas Operator | Jul 2024 |
| 341 | Ricks Exploration, Inc. | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2008 |
| 342 | Rio Petroleum, Inc. | Amarillo, TX 79102 | Oil & Gas Operator | Jul 2025 |
| 343 | Roden Oil Company | Midland, TX 79702 | Oil & Gas Operator | Feb 2008 |
| 344 | Roemer Oil Company | Denver, CO 80202 | Oil & Gas Operator | Nov 1998 |
| 345 | Rosetta Resources Operating LP | San Antonio, TX 78216 | Oil & Gas Operator | Jul 2025 |
| 346 | Rover Petroleum Operating, LLC | Plano, TX 75075 | Oil & Gas Operator | Jul 2025 |
| 347 | RTC Resources, LLP | Weatherford, OK 73096 | Oil & Gas Operator | Jul 2025 |
| 348 | Rudman Partnership, The | Dallas, TX 75201 | Oil & Gas Operator | Dec 2014 |
| 349 | S & J Operating Company | Wichita Falls, TX 76301 | Oil & Gas Operator | Mar 2015 |
| 350 | Sabine Oil & Gas LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2017 |
| 351 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 352 | Samson Contour Energy E&P, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Sep 2017 |
| 353 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 354 | Samson Lone Star LP | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2007 |
| 355 | Samson Lone Star, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Jul 2025 |
| 356 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2025 |
| 357 | Sand Springs Oil & Gas Co. | Tulsa, OK 74136 | Oil & Gas Operator | Jul 2025 |
| 358 | Sandia Operating Corp. | San Antonio, TX 78270 | Oil & Gas Operator | May 2010 |
| 359 | Sandlot Oil & Gas LLC | Gruver, TX 79040 | Oil & Gas Operator | Jul 2025 |
| 360 | Sanguine, LTD | Tulsa, OK 74170 | Gas Operator | Oct 2003 |
| 361 | Sapient Energy Corp | Oklahoma City, OK 73154 | Oil & Gas Operator | Jan 2002 |
| 362 | Sbog, LLC | Granbury, TX 76048 | Oil & Gas Operator | Feb 2021 |
| 363 | SCS Newton Oil LLC | Perryton, TX 79070 | Oil & Gas Operator | Jul 2025 |
| 364 | Scythian, LTD. | Midland, TX 79701 | Oil & Gas Operator | Dec 2020 |
| 365 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 366 | Seagull Midcon Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 367 | SFM Holdings, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Jul 1995 |
| 368 | Shannon Energy | Liberal, KS 67901 | Oil & Gas Operator | Feb 1999 |
| 369 | Shell Western E&P Inc. | Houston, TX 77001 | Oil & Gas Operator | May 2011 |
| 370 | Shidler, Mark L., Inc. | Houston, TX 77055 | Oil & Gas Operator | Jul 2025 |
| 371 | Sidwell Oil & Gas, Inc. | Amarillo, TX 79105 | Oil & Gas Operator | Sep 2014 |
| 372 | Sidwell Operating Company, L.P. | Amarillo, TX 79105 | Oil & Gas Operator | Jul 2025 |
| 373 | Slawson Exploration Company Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Jul 2025 |
| 374 | Snyder Partners | Cody, WY 82414 | Oil & Gas Operator | May 2025 |
| 375 | Sonat Exploration Co. | Houston, TX 77251 | Oil & Gas Operator | Dec 2021 |
| 376 | Sonat Exploration Company-MCR | Houston, TX 77251 | Oil & Gas Operator | Dec 1999 |
| 377 | Southwestern Energy Prod Co | Houston, TX 77032 | Oil & Gas Operator | Jun 2015 |
| 378 | Spring Resources, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jul 2007 |
| 379 | St. Johns Operating #1 L.P. | Houston, TX 77060 | Oil & Gas Operator | Aug 2023 |
| 380 | St. Mary Land & Exploration Co | Denver, CO 80201 | Oil & Gas Operator | Jun 2010 |
| 381 | St. Mary Operating Company | Denver, CO 80203 | Oil & Gas Operator | Mar 2019 |
| 382 | Statoil Oil & Gas LP | Austin, TX 78730 | Oil & Gas Operator | Oct 2018 |
| 383 | Stelbar Oil Corp | Wichita, KS 67206 | Oil & Gas Operator | Aug 1995 |
| 384 | Stephens & Johnson Operating Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | Jul 2025 |
| 385 | Stephens, Autry C. | Midland, TX 79701 | Oil & Gas Operator | Mar 2023 |
| 386 | Sting Exploration Company | Tulsa, OK 74120 | Oil Operator | Sep 2004 |
| 387 | Strat Land Exploration Company | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2025 |
| 388 | Sundance Oil & Gas, Inc. | Pampa, TX 79065 | Oil & Gas Operator | Mar 2012 |
| 389 | Sundown Energy LP | Dallas, TX 75248 | Oil & Gas Operator | Jul 2025 |
| 390 | Sundown Energy, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Mar 2025 |
| 391 | Suoco Oil Corporation | Pampa, TX 79066 | Oil & Gas Operator | Jul 2025 |
| 392 | T-Y Development Corp | Perryton, TX 79070 | Oil & Gas Operator | Jul 2025 |
| 393 | Talon Oil & Gas LLC | Dallas, TX 75243 | Oil & Gas Operator | Dec 2010 |
| 394 | TC Oil And Gas, LLC | Denton, TX 76205 | Oil Operator | Jul 2025 |
| 395 | Tecolote Energy Operating, LLC | Fort Worth, TX 76107 | Oil & Gas Operator | Jan 2024 |
| 396 | Templar Operating LLC | Oklahoma City, OK 73142 | Oil & Gas Operator | Apr 2025 |
| 397 | TGX Corporation | Houston, TX 77002 | Oil & Gas Operator | Sep 2004 |
| 398 | The Calvert Company | Oklahoma City, OK 73154-1589 | Oil & Gas Operator | Dec 2021 |
| 399 | The Quintin Little Company Inc | Ardmore, OK 73401 | Oil & Gas Operator | May 2025 |
| 400 | Thunderbird Drilling, Inc. | Wichita, KS 67207 | Oil Operator | Oct 2008 |