| 201 | Howard Exploration, Inc. | Houston, TX 77069 | Oil & Gas Operator | May 2025 |
| 202 | Huber J M Corp | Edison, NJ 08837 | Oil & Gas Operator | May 2025 |
| 203 | Hughes, Dan A. Company | Beeville, TX 78104 | Oil & Gas Operator | May 2006 |
| 204 | Hughes, Dan A. Company, L.P. | Beeville, TX 78104 | Oil & Gas Operator | May 2025 |
| 205 | Hugoton Operating Company, Inc. | Dallas, TX 75240 | Oil & Gas Operator | May 2025 |
| 206 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | May 2025 |
| 207 | Hunt Petroleum Corporation | Dallas, TX 75201 | Oil & Gas Operator | Nov 2008 |
| 208 | Hurd Enterprises, LTD. | San Antonio, TX 78209 | Oil & Gas Operator | May 2025 |
| 209 | Inexco Oil Company | Houston, TX 77210 | Oil & Gas Operator | Mar 2013 |
| 210 | Ipact | Austin, TX 78734 | Oil & Gas Operator | May 2025 |
| 211 | J G Oil & Gas | Albany, TX 76430 | Oil & Gas Operator | May 2025 |
| 212 | Jamex, Inc. | Lewisville, TX 75067 | Oil & Gas Operator | May 2025 |
| 213 | Jetta Operating Company Inc | Fort Worth, TX 76102 | Oil & Gas Operator | May 2025 |
| 214 | K.M.A. Operating, Inc. | Graham, TX 76450 | Oil & Gas Operator | Aug 2003 |
| 215 | Kaler Energy Corp. | Boerne, TX 78006 | Oil & Gas Operator | May 2025 |
| 216 | Kastman Oil Company | Lubbock, TX 79408 | Oil & Gas Operator | Nov 2012 |
| 217 | KCS Resources, Inc. | Houston, TX 77002 | Oil & Gas Operator | Feb 2009 |
| 218 | Kebo Oil & Gas, Inc. | Portland, TX 78374 | Oil & Gas Operator | May 2025 |
| 219 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | Mar 2025 |
| 220 | Kerr-McGee Oil & Gas Onshore LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2017 |
| 221 | Kerr-McGee Oil & Gas Onshore LP | Houston, TX 77046 | Oil & Gas Operator | May 2025 |
| 222 | King Ranch Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | Nov 1999 |
| 223 | King Ranch Oil & Gas, Inc. | Houston, TX 77002 | Oil & Gas Operator | Dec 1997 |
| 224 | Legacy Corporation, The | Cedar Park, TX 78613 | Oil & Gas Operator | Jun 2004 |
| 225 | Legend Natural Gas III, LP | Houston, TX 77094 | Oil & Gas Operator | Feb 2015 |
| 226 | Legend Natural Gas IV, LP | Houston, TX 77094 | Oil & Gas Operator | Feb 2015 |
| 227 | Lime Rock Resources A, L.P. | Houston, TX 77002 | Oil & Gas Operator | Feb 2025 |
| 228 | Lindenmuth & Associates Inc | Austin, TX 78703 | Oil & Gas Operator | Aug 2024 |
| 229 | Linn Operating, Inc. | Houston, TX 77002 | Oil & Gas Operator | May 2017 |
| 230 | Live Oak Reserves, Inc. | Houston, TX 77019 | Oil & Gas Operator | May 2025 |
| 231 | LMP Exploration Operating, LLC | Corpus Chrsti, TX 78477 | Oil & Gas Operator | Feb 2008 |
| 232 | Lodestone Operating | Portland, TX 78374 | Oil & Gas Operator | Mar 2025 |
| 233 | Lodestone Operating, Inc. | Portland, TX 78374 | Oil & Gas Operator | May 2025 |
| 234 | Lomak Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Aug 1998 |
| 235 | Lre Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Nov 2016 |
| 236 | LTS Oil & Gas | Lubbock, TX 79424 | Oil & Gas Operator | May 2025 |
| 237 | Lucky Lad Energy, LLC | Magnolia, TX 77353 | Oil & Gas Operator | May 2025 |
| 238 | Lundberg Operating Corporation | Dallas, TX 75225 | Oil & Gas Operator | Oct 2002 |
| 239 | M. J. G., Inc. | Alice, TX 78333 | Oil & Gas Operator | Jul 2010 |
| 240 | Maclane Gas Company L.P. | Corpus Chrsti, TX 78478 | Oil & Gas Operator | Mar 1994 |
| 241 | Maggert Energy Corp. | Spring, TX 77387 | Gas Operator | Jun 1998 |
| 242 | Magnum Engineering Company | Corpus Chrsti, TX 78401 | Oil & Gas Operator | May 2025 |
| 243 | Magnum Producing & Operating Co. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jan 2004 |
| 244 | Magnum Producing, LP | Corpus Chrsti, TX 78401 | Oil & Gas Operator | May 2025 |
| 245 | Marquise Oil Properties Inc | Konawa, OK 74849 | Oil & Gas Operator | Nov 1992 |
| 246 | Marwell Petroleum LTD Partnrship | Houston, TX 77027 | Oil & Gas Operator | May 2025 |
| 247 | Marwell Petroleum, Inc. | Houston, TX 77057 | Oil & Gas Operator | Apr 2006 |
| 248 | McCoy Petroleum Corporation | Wichita, KS 67207 | Oil & Gas Operator | Apr 2025 |
| 249 | McDaniel Company, Inc., The | Dallas, TX 75230 | Oil & Gas Operator | May 2025 |
| 250 | McDonald Production | Lubbock, TX 79408 | Oil & Gas Operator | Mar 2003 |
| 251 | McFarland & Scobey, Inc. | El Paso, TX 79947 | Oil & Gas Operator | May 2025 |
| 252 | McRae Exploration & Prod., Inc. | Houston, TX 77064 | Oil & Gas Operator | Feb 2017 |
| 253 | Melton Operating Co. | Friendswood, TX 77546 | Oil & Gas Operator | Jul 2005 |
| 254 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | May 2025 |
| 255 | Merit Energy Company, LLC | Dallas, TX 75240 | Oil & Gas Operator | Jan 2025 |
| 256 | Metano Energy, LP | San Antonio, TX 78216 | Oil & Gas Operator | Aug 2008 |
| 257 | Metco Oil Corporation | Seguin, TX 78155 | Oil Operator | Apr 2016 |
| 258 | Mexco Energy Corporation | Midland, TX 79702 | Oil & Gas Operator | Feb 2020 |
| 259 | MGF Oil Corporation | Tulsa, OK 74121 | Oil & Gas Operator | Jun 1998 |
| 260 | MGM Well Service, Inc. | Corpus Chrsti, TX 78427 | Oil & Gas Operator | Oct 2004 |
| 261 | Michael Petroleum Corporation | Houston, TX 77040 | Oil & Gas Operator | Dec 2001 |
| 262 | Midas Resources, Inc. | Corpus Chrsti, TX 78403 | Oil & Gas Operator | May 2025 |
| 263 | Midpar L.P. | Midland, TX 79702 | Oil & Gas Operator | Feb 1995 |
| 264 | Midstates Corporation | San Antonio, TX 78217 | Oil & Gas Operator | May 2025 |
| 265 | Milagro Exploration, LLC | Houston, TX 77010 | Oil & Gas Operator | Aug 2018 |
| 266 | Milo-Austintatious | Houston, TX 77005 | Oil & Gas Operator | Aug 2006 |
| 267 | Miramar Petroleum, Inc. | Corpus Chrsti, TX 78463 | Oil & Gas Operator | Sep 2017 |
| 268 | Mission River Systems, Inc. | Corpus Chrsti, TX 78473 | Oil & Gas Operator | May 2025 |
| 269 | Mitchell Energy Company L.P. | Spring, TX 77387 | Oil & Gas Operator | Mar 2008 |
| 270 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 271 | Mobil Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2016 |
| 272 | Mobil Producing TX. & N.M. Inc. | Spring, TX 77389 | Oil & Gas Operator | May 2025 |
| 273 | Modena Operating LLC | Houston, TX 77057 | Oil & Gas Operator | May 2025 |
| 274 | Momentum Production Corp. | Baytown, TX 77521 | Oil & Gas Operator | May 2025 |
| 275 | Mortimer Exploration Company | San Antonio, TX 78209 | Oil & Gas Operator | Sep 2003 |
| 276 | Mueller Engineering Corp. | Corpus Chrsti, TX 78476 | Oil & Gas Operator | Feb 2002 |
| 277 | Mueller Exploration, Inc. | Portland, TX 78374 | Oil & Gas Operator | May 2025 |
| 278 | MW Petroleum Corporation | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |
| 279 | Nadcf Recovery Group, Inc. | Chapin, SC 29036 | Oil & Gas Operator | May 2025 |
| 280 | Neuhaus, V. F. Properties, Inc. | Palmhurst, TX 78573 | Oil & Gas Operator | Dec 2022 |
| 281 | Neumin Production Company | Point Comfort, TX 77978 | Oil & Gas Operator | May 2025 |
| 282 | New Height Energy, LLC | Houston, TX 77063 | Oil & Gas Operator | May 2025 |
| 283 | Newfield Exploration Company | The Woodlands, TX 77380 | Oil & Gas Operator | Jun 2017 |
| 284 | Noble Energy Inc | Midland, TX 79706 | Oil & Gas Operator | May 2025 |
| 285 | Nordstrand Engineering Inc | Houston, TX 77019 | Oil & Gas Operator | May 2025 |
| 286 | North Central Oil Corp | Houston, TX 77252 | Oil & Gas Operator | Dec 2005 |
| 287 | Northern Pacific Oil And Gas Incorporated | Houston, TX 77024 | Oil & Gas Operator | Dec 2022 |
| 288 | O'Benco, Inc. | Shreveport, LA 71136 | Oil & Gas Operator | May 2025 |
| 289 | O'Sullivan Oil & Gas Co., Inc. | Houston, TX 77002 | Oil & Gas Operator | Oct 2000 |
| 290 | Ocean Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | Aug 2003 |
| 291 | Omega Energy Corp. | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 292 | Omega Energy, LLC | Corpus Chrsti, TX 78418 | Oil & Gas Operator | May 2025 |
| 293 | Omimex Petroleum Inc | Fort Worth, TX 76120 | Oil & Gas Operator | Aug 2022 |
| 294 | Orx Resources, L.L.C. | Houston, TX 77067 | Oil & Gas Operator | May 2025 |
| 295 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 296 | Osborn Heirs Co | San Antonio, TX 78217 | Oil & Gas Operator | Mar 2025 |
| 297 | Outline Oil Corp. | San Antonio, TX 78217 | Oil & Gas Operator | May 2025 |
| 298 | Owl Creek Production Co., Inc. | Houston, TX 77027 | Oil & Gas Operator | Apr 2006 |
| 299 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | May 2025 |
| 300 | Pactola Development Co | Tulsa, OK 74159 | Oil & Gas Operator | Sep 2004 |