| 201 | Mark IV Energy | San Antonio, TX 78213 | Oil & Gas Operator | Apr 1993 |
| 202 | Marshall & Winston, Inc. | Midland, TX 79710 | Oil & Gas Operator | May 2025 |
| 203 | Martin Gas Sales, Inc. | Kilgore, TX 75662 | Oil & Gas Operator | May 1993 |
| 204 | Martineau Petroleum, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Jan 2025 |
| 205 | Matador Production Company | Dallas, TX 75240 | Oil & Gas Operator | Jul 2025 |
| 206 | Maverick Energy Group, Inc. | Tulsa, OK 74103 | Oil & Gas Operator | Jul 2025 |
| 207 | MB Energy, LLC | San Antonio, TX 78233 | Oil & Gas Operator | Jul 2025 |
| 208 | McDaniel Company, Inc., The | Dallas, TX 75230 | Oil & Gas Operator | Jul 2025 |
| 209 | McDay Energy Corp. | Dallas, TX 75206 | Oil & Gas Operator | Jul 2025 |
| 210 | McEna Inc | Tulsa, OK 74135 | Oil & Gas Operator | Jul 2005 |
| 211 | McFarland Energy, Inc. | New Orleans, LA 70160 | Oil & Gas Operator | Dec 2009 |
| 212 | Melton, Joe, DRLG. Co., Inc. | Midland, TX 79704 | Oil & Gas Operator | Dec 2004 |
| 213 | Meridian Oil Inc. | Houston, TX 77210 | Oil & Gas Operator | Aug 1996 |
| 214 | Merzbacher, George F. Jr. | Robstown, TX 78380 | Oil & Gas Operator | May 1994 |
| 215 | Mestena Operating, LTD. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jun 2009 |
| 216 | Metis Energy LLC | Houston, TX 77019 | Oil & Gas Operator | Jul 2025 |
| 217 | Mextex Operating Company | Austin, TX 78734 | Oil & Gas Operator | Jul 2025 |
| 218 | Midwestern Exploration Co. | Edmond, OK 73013 | Oil & Gas Operator | Mar 2025 |
| 219 | Millennium Petro-Physics, Inc. | Corpus Chrsti, TX 78480 | Oil & Gas Operator | Jul 2025 |
| 220 | Mission River Systems, Inc. | Corpus Chrsti, TX 78473 | Oil & Gas Operator | Jul 2025 |
| 221 | Mobil Producing TX. & N.M. Inc. | Spring, TX 77389 | Oil & Gas Operator | Jul 2025 |
| 222 | Momentum Production Corp. | Baytown, TX 77521 | Oil & Gas Operator | Jul 2025 |
| 223 | Moran-Lavaca, L.L.C. | Shreveport, LA 71134 | Oil Operator | Feb 2018 |
| 224 | Mortimer Exploration Company | San Antonio, TX 78209 | Oil & Gas Operator | Sep 2003 |
| 225 | Mortimer Production Company | San Antonio, TX 78209 | Oil & Gas Operator | Jul 2025 |
| 226 | Mueller Engineering Corp. | Corpus Chrsti, TX 78476 | Oil & Gas Operator | Feb 2002 |
| 227 | Mueller Exploration, Inc. | Portland, TX 78374 | Oil & Gas Operator | Jul 2025 |
| 228 | Munoz Farms Operating Co., LLC | Carrizo SPGS, TX 78834 | Oil & Gas Operator | Jul 2025 |
| 229 | MWJ Producing Company | Midland, TX 79701 | Oil & Gas Operator | Jul 1998 |
| 230 | Nails Operating Company LLC | Hondo, TX 78861 | Oil Operator | Jul 2025 |
| 231 | Nasser Oil & Gas, Inc. | The Woodlands, TX 77380 | Oil & Gas Operator | Apr 1998 |
| 232 | National Surface & Minerals, LLC | Addison, TX 75001 | Gas Operator | Jan 2023 |
| 233 | Newfield Exploration Company | The Woodlands, TX 77380 | Oil & Gas Operator | Jun 2017 |
| 234 | Nichols,Edwin S Explorations Inc | Graham, TX 76450 | Oil & Gas Operator | Jul 2025 |
| 235 | O.G.P. Operating, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Jul 2025 |
| 236 | Oakland Petroleum Oper Co., Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Jul 2025 |
| 237 | Oilton Resources, Inc. | Laredo, TX 78041 | Oil & Gas Operator | Jul 2025 |
| 238 | Okla. Magic Circle Energy Corp. | Shawnee, OK 74801 | Oil & Gas Operator | Jul 2004 |
| 239 | Omni Operating Company(A) | Dallas, TX 75370 | Oil & Gas Operator | Jul 2025 |
| 240 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 241 | Osborne Oil Co. | Dallas, TX 75244 | Oil & Gas Operator | Aug 2003 |
| 242 | Osyka Oil & Gas, Inc. | Metairie, LA 70004 | Oil & Gas Operator | Jul 2025 |
| 243 | Overly Operating Co. | San Antonio, TX 78209 | Oil & Gas Operator | Jul 2013 |
| 244 | Overstreet, Jamie L | Hondo, TX 78861 | Oil & Gas Operator | Jul 2025 |
| 245 | Oxson Co. | Uvalde, TX 78802 | Gas Operator | Jul 2025 |
| 246 | Pacific Operators, Inc. | San Antonio, TX 78205 | Oil & Gas Operator | Mar 1999 |
| 247 | Patrick Exploration Company | Tulsa, OK 74136 | Oil & Gas Operator | Apr 2011 |
| 248 | Patterson Energy Corporation | Dallas, TX 75205 | Oil & Gas Operator | Jul 2025 |
| 249 | Patterson Petroleum LLC | Snyder, TX 79550 | Oil & Gas Operator | Oct 2007 |
| 250 | Patterson Petroleum LP | Snyder, TX 79550 | Oil & Gas Operator | Mar 2008 |
| 251 | Pearl, Bill H. Productions, Inc. | Corpus Chrsti, TX 78460 | Oil & Gas Operator | Jul 2025 |
| 252 | Petrohawk Operating Company | Houston, TX 77056 | Oil & Gas Operator | Oct 2021 |
| 253 | Petrolero Corp. | San Antonio, TX 78205 | Oil & Gas Operator | Feb 1998 |
| 254 | Petronomics Petroleum, Inc. | Austin, TX 78734 | Oil & Gas Operator | Jan 1995 |
| 255 | Phoenix Fund, Inc. | San Antonio, TX 78217 | Oil & Gas Operator | Jun 2000 |
| 256 | Phoenix Operating Company Of TX. | Dallas, TX 75206 | Oil & Gas Operator | Jun 1995 |
| 257 | Pickens Company, Inc., The | Dallas, TX 75225 | Oil & Gas Operator | Dec 2024 |
| 258 | Picosa, L.L.C. | Carrizo SPGS, TX 78834 | Oil & Gas Operator | Jul 2025 |
| 259 | Pioneer Exploration Company | Houston, TX 77090 | Oil & Gas Operator | May 2025 |
| 260 | Pioneer Exploration, LLC | Houston, TX 77090 | Oil & Gas Operator | May 2025 |
| 261 | Pioneer Exploration, LTD. | Houston, TX 77090 | Oil & Gas Operator | Sep 2008 |
| 262 | Plains Marketing, LP | Cushing, OK 74023 | Oil Operator | Jan 2012 |
| 263 | Plano Petroleum Corporation | McKinney, TX 75070 | Oil & Gas Operator | Feb 2025 |
| 264 | PNG Operating Company | Oklahoma City, OK 73172 | Oil & Gas Operator | Jul 2025 |
| 265 | Prime Operating Company | Houston, TX 77024 | Oil & Gas Operator | Jul 2025 |
| 266 | Producers Engineering Company | Destin, FL 32541 | Oil & Gas Operator | Sep 1999 |
| 267 | Production Resources, Inc. | Castroville, TX 78009 | Oil & Gas Operator | Jul 2025 |
| 268 | Property Development Group, Inc. | San Antonio, TX 78212 | Oil & Gas Operator | Jul 2025 |
| 269 | Pyramid Energy Inc | San Antonio, TX 78216 | Oil & Gas Operator | Feb 2012 |
| 270 | Quail Well Service, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Jul 2025 |
| 271 | Quatro Oil And Gas, Inc. | Joshua, TX 76058 | Oil & Gas Operator | Jul 2025 |
| 272 | R. K. G. Engineering, Inc. | Odessa, TX 79760 | Oil & Gas Operator | Jul 2025 |
| 273 | R.B.S. Oil & Gas Inc. | San Antonio, TX 78278 | Oil & Gas Operator | Jul 2025 |
| 274 | R.C.I. Energy | Alice, TX 78333 | Oil & Gas Operator | Jul 2025 |
| 275 | Rec, LLC | Pleasanton, TX 78064 | Oil & Gas Operator | Jul 2025 |
| 276 | Red Byrd Oil, LLC | Crystal City, TX 78839 | Oil Operator | Jul 2025 |
| 277 | Redrock Exploration, Inc | Plano, TX 75025 | Oil Operator | Jul 2014 |
| 278 | Regal Petroleum Services | Euless, TX 76039 | Oil & Gas Operator | Aug 2002 |
| 279 | Regency Energy, Inc. | Crystal City, TX 78839 | Oil & Gas Operator | Jul 2025 |
| 280 | Remuda Operating Company | Midland, TX 79711 | Oil & Gas Operator | Jul 2025 |
| 281 | Reo Operating LLC | Austin, TX 78747 | Oil & Gas Operator | Jul 2025 |
| 282 | Retama Oil Corporation | Uvalde, TX 78801 | Oil & Gas Operator | Jul 2025 |
| 283 | Rexcom, Inc. | San Antonio, TX 78217 | Oil & Gas Operator | Jul 2025 |
| 284 | Rickaway Energy, Corp. | Pleasanton, TX 78064 | Oil & Gas Operator | Jul 2025 |
| 285 | Ricochet Energy, Inc. | San Antonio, TX 78258 | Oil & Gas Operator | Jul 2025 |
| 286 | Rife, M. O., Jr. | Fort Worth, TX 76107 | Oil & Gas Operator | Dec 1998 |
| 287 | Riley Exploration, LLC | Blanchard, OK 73010 | Oil & Gas Operator | Jul 2025 |
| 288 | Rio Grand Exploration, LLC | San Antonio, TX 78216 | Oil & Gas Operator | Jul 2025 |
| 289 | Rio-Tex, Inc. | San Antonio, TX 78217 | Oil & Gas Operator | Jul 2025 |
| 290 | Rivercity Operating, Inc. | Austin, TX 78766 | Oil & Gas Operator | Jul 2025 |
| 291 | Rme Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Nov 2016 |
| 292 | Roma Oil And Gas, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Jul 2025 |
| 293 | Rosewood Resources, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Jul 2025 |
| 294 | S & L Oil Field Services | Carrizo SPGS, TX 78834 | Oil & Gas Operator | Jan 1999 |
| 295 | Sabco Operating Company | Houston, TX 77056 | Oil & Gas Operator | Oct 2011 |
| 296 | Sabco Operating Company, LLC | Houston, TX 77056 | Oil & Gas Operator | Jun 2018 |
| 297 | Sabinal Resources, Inc. | Kingwood, TX 77339 | Oil & Gas Operator | Jul 2025 |
| 298 | Sage Energy Company | San Antonio, TX 78215 | Oil & Gas Operator | Jul 2025 |
| 299 | San Antonio Gas & Oil, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Feb 2000 |
| 300 | Sanchez Oil & Gas Corporation | Houston, TX 77056 | Oil & Gas Operator | Jul 2025 |