| 201 | McGowan Working Partners | Jackson, MS 39296 | Oil & Gas Operator | Dec 2000 |
| 202 | McGowan Working Partners, Inc. | Jackson, MS 39296 | Oil & Gas Operator | Dec 2025 |
| 203 | Meason Operating Company | Natchez, MS 39121 | Oil & Gas Operator | Dec 2011 |
| 204 | Mid-Continent Energy, Inc. | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2020 |
| 205 | Minatome Corpora | | Oil & Gas Operator | Sep 1987 |
| 206 | Miss-Lou Operating LLC | | Oil & Gas Operator | Sep 2025 |
| 207 | Mobil E&P North America Inc. | | Oil & Gas Operator | Jan 1994 |
| 208 | Mobil Oil E & P Southeast Inc | | Oil & Gas Operator | Sep 2013 |
| 209 | Monterey Pipeline Co. | | Oil Operator | Aug 1993 |
| 210 | Newhaven Operating Inc | | Oil & Gas Operator | Dec 1998 |
| 211 | Newport Operators, LLC | | Oil & Gas Operator | Jan 2019 |
| 212 | North American Royalties, Inc. | Chattanooga, TN 37408 | Oil & Gas Operator | Oct 2001 |
| 213 | Northcott Exploration Co. Inc. | | Oil & Gas Operator | Dec 1987 |
| 214 | Oasis Production Co., Inc. | | Oil & Gas Operator | Jun 1988 |
| 215 | Oil & Gas Development Company | | Oil & Gas Operator | May 1991 |
| 216 | Oil & Gas Property MGMT., Inc. | Dallas, TX 75201 | Oil & Gas Operator | Jul 1996 |
| 217 | Oil Recovery, Inc. | | Oil Operator | Sep 1992 |
| 218 | Oldfield Operating Corporation | | Oil Operator | Dec 2013 |
| 219 | Oleum Inc | | Oil & Gas Operator | Mar 1996 |
| 220 | Oleum Operating La LLC | | Oil & Gas Operator | Nov 2022 |
| 221 | Olipdp II, LLC | Lafayette, LA 70503 | Oil & Gas Operator | Dec 2025 |
| 222 | Omega Energy Corp. | Graham, TX 76450 | Oil & Gas Operator | Dec 2025 |
| 223 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 224 | P & P Producing Inc | Midland, TX 79702 | Oil & Gas Operator | Feb 2015 |
| 225 | P.C.S.I. | | Oil & Gas Operator | Jun 1987 |
| 226 | Pacific Enterprises Oil Co USA | Dallas, TX 75201 | Oil & Gas Operator | Feb 2001 |
| 227 | Pacific Enterprises Royalty Co | Oklahoma City, OK 73101 | Oil & Gas Operator | Feb 2002 |
| 228 | Palmer Petroleum, Inc. | Shreveport, LA 71105 | Oil & Gas Operator | Jun 2025 |
| 229 | Panther Bayou Energy, LLC | Houston, TX 77070 | Oil & Gas Operator | Apr 2021 |
| 230 | Par Exploration Co | | Oil & Gas Operator | Oct 1986 |
| 231 | Parker & Parsley Devpt L P | | Oil & Gas Operator | Oct 1997 |
| 232 | Parnes Oil Company | | Oil Operator | Jul 1994 |
| 233 | Paxton Oil Company | | Oil & Gas Operator | Dec 2024 |
| 234 | Paxton Petroleum, LTD. | | Oil & Gas Operator | May 1989 |
| 235 | Pay Oil, L. L. C. | | Oil & Gas Operator | Jan 2025 |
| 236 | Pengo Petroleum Inc | | Oil & Gas Operator | Dec 2013 |
| 237 | Pennington Oil & Gas Int, LLC | | Oil & Gas Operator | Dec 2024 |
| 238 | Pennington Operating Company, LLC | | Oil & Gas Operator | Jul 2020 |
| 239 | Perdure Petroleum LLC | Allen, TX 75013 | Oil & Gas Operator | Oct 2021 |
| 240 | Petro "E", LLC | | Oil & Gas Operator | Feb 2010 |
| 241 | Petro Harvester Operating Company, LLC | | Oil & Gas Operator | Nov 2022 |
| 242 | Petro-Guard Production,L.L.C. | Houston, TX 77063 | Oil & Gas Operator | Dec 2024 |
| 243 | Petro-Lewis Corp. | | Oil & Gas Operator | Feb 1994 |
| 244 | Petro-Search, Inc. | | Oil Operator | Jul 1992 |
| 245 | Petrodome Operating, LLC | Houston, TX 77265 | Oil & Gas Operator | Jun 2025 |
| 246 | Petroleum Engineers, Inc. | | Oil & Gas Operator | Jun 1983 |
| 247 | Petroleum Exchange | | Oil & Gas Operator | Oct 1997 |
| 248 | Petroleum Management Int'L, Inc. | Sugar Land, TX 77487 | Oil & Gas Operator | Oct 1993 |
| 249 | Petroleum Properties MGMT Corp | | Oil & Gas Operator | Aug 1990 |
| 250 | Petroleum Resources MGMT Corp. | | Oil & Gas Operator | Mar 2002 |
| 251 | Phillips Energy, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2018 |
| 252 | Pickens Company, Inc., The | Dallas, TX 75225 | Oil & Gas Operator | Jan 2025 |
| 253 | Pie La Operating, LLC | | Oil & Gas Operator | Jan 2025 |
| 254 | Planet Operating, LLC | | Oil & Gas Operator | Dec 2024 |
| 255 | Plumb Operating Company, Inc. | | Oil & Gas Operator | Dec 1989 |
| 256 | Post Petroleum Company | Oklahoma City, OK 73116 | Oil & Gas Operator | Aug 2013 |
| 257 | Presidio Exploration, Inc. | Englewood, CO 80155 | Oil & Gas Operator | May 1999 |
| 258 | Prime Rock Resources La LLC | | Oil & Gas Operator | Dec 2024 |
| 259 | Professional Petr. Servs, Inc. | | Oil Operator | Oct 2016 |
| 260 | Pryme Energy, LLC | | Oil & Gas Operator | Feb 2015 |
| 261 | Quest Exploration L.L.C. | | Oil & Gas Operator | Jul 2014 |
| 262 | R & B Oil Company, LLC Of Texas | | Oil & Gas Operator | Jan 2025 |
| 263 | R&R Resources Corporation | Houston, TX 77056 | Oil & Gas Operator | Dec 2015 |
| 264 | Range Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2021 |
| 265 | Republic Mineral Corporation | | Oil & Gas Operator | Sep 1987 |
| 266 | Resource Securities Corp. | | Oil & Gas Operator | Mar 2005 |
| 267 | Resources Investment Corp | Denver, CO 80202 | Oil & Gas Operator | Sep 2018 |
| 268 | Rig Iron, Inc. | | Oil & Gas Operator | Mar 1991 |
| 269 | Robert L. Waterbury | | Oil & Gas Operator | Nov 2001 |
| 270 | Robert L. Waterbury, L.L.C. | | Oil & Gas Operator | Dec 2024 |
| 271 | Roppolo Petro/Sun Explor& Prod | | Oil & Gas Operator | Sep 1988 |
| 272 | Rozel Operating Company | | Oil & Gas Operator | Oct 2014 |
| 273 | Rse, Inc. | Houston, TX 77077 | Oil & Gas Operator | Sep 2000 |
| 274 | Sabine Corporation | Oklahoma City, OK 73116 | Oil & Gas Operator | Jul 1996 |
| 275 | Samson Contour Energy E&P, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Sep 2017 |
| 276 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Oct 2025 |
| 277 | Santa Fe Braun Inc | Dallas, TX 75240-6620 | Oil & Gas Operator | Mar 1995 |
| 278 | Santos USA Corp. | Houston, TX 77042 | Oil & Gas Operator | Dec 2008 |
| 279 | Secondary Recovery, Inc. | | Oil & Gas Operator | Dec 1991 |
| 280 | Sevarg Company, Inc. | | Oil & Gas Operator | Feb 2016 |
| 281 | Shale Energy International, LLC | | Oil & Gas Operator | Nov 2024 |
| 282 | Shelf Energy, LLC | | Oil & Gas Operator | Dec 2024 |
| 283 | Shell Oil Co. | Houston, TX 77001 | Oil & Gas Operator | Jun 1985 |
| 284 | Shell Western E&P Inc. | Houston, TX 77001 | Oil & Gas Operator | May 2011 |
| 285 | Shuteston Oil & Gas | | Oil & Gas Operator | Sep 1997 |
| 286 | SKZ Inc. | | Oil Operator | Mar 1988 |
| 287 | Sohio Petr Co-Gulf Oil Corp | | Oil & Gas Operator | Dec 1979 |
| 288 | Sohio Petroleum Co. | Casper, WY 82602 | Oil & Gas Operator | Apr 1986 |
| 289 | Sooner Resources, Inc. | | Oil & Gas Operator | Mar 1987 |
| 290 | Source Petroleum Inc. | San Antonio, TX 78265 | Oil & Gas Operator | Dec 2025 |
| 291 | South La. Production Co., Inc. | | Oil & Gas Operator | Jun 1982 |
| 292 | Southern Wells, Inc. | | Oil Operator | Sep 2002 |
| 293 | Southwest Oil Properties, Inc. | | Oil & Gas Operator | Feb 1996 |
| 294 | Southwest Rig Service | | Oil & Gas Operator | Nov 1998 |
| 295 | Southwestern Energy Prod Co | Houston, TX 77032 | Oil & Gas Operator | Jun 2015 |
| 296 | SRP Production Corp. | | Oil & Gas Operator | Nov 1997 |
| 297 | St. Paul Oil And Gas Corp. | | Oil & Gas Operator | Aug 1991 |
| 298 | Star Energy Inc | Dayton, PA 16222-4325 | Oil & Gas Operator | Dec 2024 |
| 299 | Strand Energy, L.C. | Houston, TX 77002 | Oil & Gas Operator | Dec 2025 |
| 300 | Stratco Operating Co Inc | Austin, TX 78701 | Oil & Gas Operator | Dec 2025 |