| 201 | Hilcorp Energy Company | Houston, TX 77208 | Oil & Gas Operator | Mar 2025 |
| 202 | Hollimon Oil Corporation | Castroville, TX 78009 | Oil & Gas Operator | Nov 2016 |
| 203 | Houston Expl. & Prod. Co., Inc. | Austin, TX 78746 | Oil & Gas Operator | Aug 2003 |
| 204 | Houston Hydrocarbons, Inc. (A) | Houston, TX 77042 | Oil & Gas Operator | Sep 2004 |
| 205 | Houston Oil & Minerals Corp. | Houston, TX 77002 | Oil & Gas Operator | Aug 1996 |
| 206 | HRB Operating Company Inc | Bridgeport, TX 76426 | Oil & Gas Operator | Mar 2025 |
| 207 | Hughes, Dan A. Company | Beeville, TX 78104 | Oil & Gas Operator | May 2006 |
| 208 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Mar 2025 |
| 209 | Hunt, WM. Herbert, Trust Est. | Dallas, TX 75201 | Oil & Gas Operator | Sep 1998 |
| 210 | Hunters Creek Oil & Gas | Houston, TX 77042 | Oil & Gas Operator | Mar 2025 |
| 211 | Imperial Oil Company | Houston, TX 77073 | Oil & Gas Operator | Oct 2004 |
| 212 | Inexco Oil Company | Houston, TX 77210 | Oil & Gas Operator | Mar 2013 |
| 213 | Infinity Hydrocarbons LLC | Houston, TX 77079 | Oil & Gas Operator | Aug 2022 |
| 214 | Inland Gas Corp. | Houston, TX 77036 | Oil Operator | Dec 2011 |
| 215 | Inland Minerals Management, Inc. | Austin, TX 78701 | Oil & Gas Operator | Mar 2025 |
| 216 | Intercity Management Corp. | Corpus Chrsti, TX 78412 | Oil & Gas Operator | Mar 2025 |
| 217 | Intercoast Oil And Gas Company | Tulsa, OK 74136 | Oil & Gas Operator | Jun 1997 |
| 218 | Ipact | Austin, TX 78734 | Oil & Gas Operator | Mar 2025 |
| 219 | Island Exploration | Houston, TX 77058 | Oil & Gas Operator | Mar 2025 |
| 220 | J G Oil & Gas | Albany, TX 76430 | Oil & Gas Operator | Mar 2025 |
| 221 | J-W Operating Company | Christoval, TX 76935 | Oil & Gas Operator | Mar 2025 |
| 222 | J.F.S. Production Co., Inc. | Houston, TX 77027 | Oil & Gas Operator | Apr 1995 |
| 223 | J.R. Oil Company | Houston, TX 77007 | Oil & Gas Operator | Jul 2019 |
| 224 | Jamex, Inc. | Lewisville, TX 75067 | Oil & Gas Operator | Mar 2025 |
| 225 | Jet Oil Producers, Inc. | Coldspring, TX 77331 | Oil & Gas Operator | Mar 2025 |
| 226 | JMC Resources Corp. | Houston, TX 77077 | Oil & Gas Operator | Mar 2025 |
| 227 | Josey Oil Company | Houston, TX 77019 | Oil & Gas Operator | Jul 2006 |
| 228 | Josey Oil Company, LTD. | Houston, TX 77019 | Oil & Gas Operator | Mar 2025 |
| 229 | Josey, Lenoir M., Inc. | Houston, TX 77019 | Oil & Gas Operator | Aug 2003 |
| 230 | Joy Resources, Inc. | Houston, TX 77027 | Oil & Gas Operator | Mar 2025 |
| 231 | Kaiser-Francis Oil Company | Tulsa, OK 74121 | Oil & Gas Operator | Mar 2025 |
| 232 | KCS Medallion Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Nov 2018 |
| 233 | KCS Resources, Inc. | Houston, TX 77002 | Oil & Gas Operator | Feb 2009 |
| 234 | Kebo Oil & Gas, Inc. | Portland, TX 78374 | Oil & Gas Operator | Mar 2025 |
| 235 | Keen Operating Company, Inc. | Austin, TX 78705 | Oil & Gas Operator | Aug 2001 |
| 236 | Kestrel Resources, Inc. | Dallas, TX 75204 | Oil & Gas Operator | Jan 2017 |
| 237 | Kinder Morgan Tejas Pipeline LLC | Houston, TX 77002 | Oil & Gas Operator | Mar 2025 |
| 238 | King Operating Corporation | Fort Worth, TX 76147 | Oil & Gas Operator | Mar 2025 |
| 239 | KP Exploration, Inc. | Houston, TX 77002 | Oil & Gas Operator | Apr 1997 |
| 240 | Lee Brothers Oil Co. | Houston, TX 77056 | Oil & Gas Operator | Mar 2008 |
| 241 | Legend Natural Gas II, LP | Houston, TX 77094 | Oil & Gas Operator | Feb 2015 |
| 242 | Leonard, J. A. | Austin, TX 78734 | Oil & Gas Operator | Mar 2025 |
| 243 | Levinson Partners Corporation | Denver, CO 80202 | Oil & Gas Operator | Jul 1995 |
| 244 | LGDC Corporation | Shreveport, LA 71101 | Oil & Gas Operator | Mar 2025 |
| 245 | Linc Gulf Coast Petroleum, Inc. | Katy, TX 77494 | Oil & Gas Operator | Mar 2025 |
| 246 | Lindow Oil & Gas, LLC | Caldwell, TX 77836 | Oil & Gas Operator | Mar 2025 |
| 247 | Live Oak Op & Production, L.L.C. | Austin, TX 78759 | Oil & Gas Operator | Nov 2011 |
| 248 | Llog Exploration Texas, L.P. | Covington, LA 70433 | Oil & Gas Operator | Mar 2025 |
| 249 | Loin Energy Corporation | La Grange, TX 78945 | Oil & Gas Operator | Mar 2025 |
| 250 | Lone Wolf Operating Company | Denver, CO 80202 | Oil & Gas Operator | Nov 2005 |
| 251 | Lone Wolf Operating Company, LP | Haxtun, CO 80731 | Oil & Gas Operator | Sep 2009 |
| 252 | Lozano Oil Company Inc. | Houston, TX 77082 | Oil & Gas Operator | Mar 2025 |
| 253 | LT Oil LLC | San Marcos, TX 78666 | Oil Operator | Mar 2025 |
| 254 | LTX Productions, Inc. | Houston, TX 77095 | Oil & Gas Operator | Jul 2008 |
| 255 | Lucky Lad Energy, LLC | Magnolia, TX 77353 | Oil & Gas Operator | Mar 2025 |
| 256 | Lynx Energy Company, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Mar 2008 |
| 257 | M & R Exploration Company | Houston, TX 77074 | Oil & Gas Operator | Aug 2003 |
| 258 | M. J. G., Inc. | Alice, TX 78333 | Oil & Gas Operator | Jul 2010 |
| 259 | Magnum Producing & Operating Co. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jan 2004 |
| 260 | Magnum Producing, LP | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Mar 2025 |
| 261 | Magruder, Edwin H., Jr. | Midland, TX 79701 | Oil & Gas Operator | Oct 2019 |
| 262 | Maguire Oil Company | Dallas, TX 75270 | Oil & Gas Operator | Mar 2015 |
| 263 | Main Energy, Inc. | Houston, TX 77079 | Oil & Gas Operator | May 2009 |
| 264 | Maralo, Inc. | Midland, TX 79702 | Oil & Gas Operator | Dec 1998 |
| 265 | Marathon Oil Company | Houston, TX 77024 | Oil & Gas Operator | Jan 2025 |
| 266 | Marquee Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2025 |
| 267 | Marshall Petroleum, Inc. | Houston, TX 77040 | Oil & Gas Operator | Aug 2003 |
| 268 | Marshall, A. B. | Houston, TX 77050 | Oil & Gas Operator | Sep 1995 |
| 269 | Marwell Petroleum LTD Partnrship | Houston, TX 77027 | Oil & Gas Operator | Mar 2025 |
| 270 | Marwell Petroleum, Inc. | Houston, TX 77057 | Oil & Gas Operator | Apr 2006 |
| 271 | Maxim Energy Corporation | Baytown, TX 77520 | Oil & Gas Operator | Dec 2024 |
| 272 | MBX Operating LLC | Houston, TX 77007 | Oil & Gas Operator | Mar 2025 |
| 273 | McCarter, A. Nelson | Houston, TX 77063 | Oil & Gas Operator | Aug 2003 |
| 274 | McDay Energy Corp. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2025 |
| 275 | McDonald Production | Lubbock, TX 79408 | Oil & Gas Operator | Mar 2003 |
| 276 | McLeod, George L. Inc. | Houston, TX 77079 | Oil & Gas Operator | Sep 2002 |
| 277 | McRae Exploration & Prod., Inc. | Houston, TX 77064 | Oil & Gas Operator | Feb 2017 |
| 278 | Medallion Production Company | Tulsa, OK 74103 | Oil & Gas Operator | May 1997 |
| 279 | Memorial Exploration Company | Saint Louis, MO 63105 | Oil & Gas Operator | Aug 1996 |
| 280 | Merenco | Midland, TX 79702 | Oil & Gas Operator | Dec 1996 |
| 281 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Mar 2025 |
| 282 | Midpar L.P. | Midland, TX 79702 | Oil & Gas Operator | Feb 1995 |
| 283 | Milagro Exploration, LLC | Houston, TX 77010 | Oil & Gas Operator | Aug 2018 |
| 284 | Mission Resources Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2008 |
| 285 | Mission River Systems, Inc. | Corpus Chrsti, TX 78473 | Oil & Gas Operator | Mar 2025 |
| 286 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 287 | MJ Oil, Inc. | Houston, TX 77265 | Oil & Gas Operator | Mar 2025 |
| 288 | Mobil Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2016 |
| 289 | Mobil Producing TX. & N.M. Inc. | Spring, TX 77389 | Oil & Gas Operator | Mar 2025 |
| 290 | Mojac Energy Corp. | Houston, TX 77056 | Oil & Gas Operator | Dec 1997 |
| 291 | Morgan Enterprises, Inc. | Houston, TX 77024 | Oil & Gas Operator | Mar 2025 |
| 292 | Mosbacher Energy Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2025 |
| 293 | Moses, Tom | Beaumont, TX 77702 | Oil Operator | Mar 2025 |
| 294 | Mse Operating Corp. | Beaverton, OR 97008 | Oil & Gas Operator | Mar 2025 |
| 295 | MW Petroleum Corporation | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |
| 296 | Nance Engineering Inc. | Houston, TX 77058 | Oil & Gas Operator | Mar 2002 |
| 297 | Natural Gas MKTG. & Storage Co. | Houston, TX 77251 | Oil & Gas Operator | Sep 1996 |
| 298 | Neostar Energy Co. | Crossville, TN 38572 | Oil & Gas Operator | Feb 2019 |
| 299 | Neumin Production Company | Point Comfort, TX 77978 | Oil & Gas Operator | Mar 2025 |
| 300 | New Century Exploration, Inc. | Spring, TX 77379 | Oil & Gas Operator | Mar 2025 |