| 201 | Harper Hefte, Inc. | Corpus Chrsti, TX 78410 | Oil & Gas Operator | May 2025 |
| 202 | Harrigan Operating, LLC | Houston, TX 77258 | Oil & Gas Operator | Apr 2020 |
| 203 | Harris Energy Services, LLC | Dallas, TX 75201 | Oil & Gas Operator | May 2025 |
| 204 | Hart Petroleum Services, Inc | Robstown, TX 78380 | Oil & Gas Operator | May 2025 |
| 205 | Harvey Brothers Oil & Gas | Corpus Chrsti, TX 78408 | Oil & Gas Operator | Jul 2004 |
| 206 | Harvey, Mike W. Oil & Gas | Corpus Chrsti, TX 78408 | Oil & Gas Operator | Aug 2003 |
| 207 | Harwood Exploration, Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Aug 1995 |
| 208 | Hawn Brothers | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Apr 2003 |
| 209 | Hawthorne Oil And Gas Corp. | Houston, TX 77227 | Oil & Gas Operator | Sep 1993 |
| 210 | Hays, T.G. Petroleum Expl., Inc. | Corpus Chrsti, TX 78476 | Oil & Gas Operator | Dec 1994 |
| 211 | Hazelett Oil Company, Inc. | Dale, TX 78616 | Oil & Gas Operator | Sep 2005 |
| 212 | Hazelett Oil, Inc. | Dale, TX 78616 | Oil & Gas Operator | Aug 2024 |
| 213 | Heartland Resources, Inc. | Temple, TX 76501 | Oil & Gas Operator | Mar 2008 |
| 214 | Hec Petroleum, Inc | Midland, TX 79705 | Oil & Gas Operator | Mar 2006 |
| 215 | Hedrick Production Inc. | Corpus Chrsti, TX 78403 | Oil & Gas Operator | May 2025 |
| 216 | Hewitt, Robert J. | Victoria, TX 77901 | Oil & Gas Operator | Jun 2004 |
| 217 | High Island Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Jun 2017 |
| 218 | High Plains Gas Systems, Inc. | Houston, TX 77019 | Oil & Gas Operator | May 2025 |
| 219 | HK Energy Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | May 2023 |
| 220 | Home Petroleum Corp | Victoria, TX 77902 | Oil & Gas Operator | May 2025 |
| 221 | Horizon Exploration Company | Houston, TX 77019 | Oil & Gas Operator | Aug 2002 |
| 222 | Howard Exploration, Inc. | Houston, TX 77069 | Oil & Gas Operator | May 2025 |
| 223 | Howard, Douglas J. | Houston, TX 77070 | Oil & Gas Operator | Mar 2008 |
| 224 | Huber Energy L.P. | Houston, TX 77079 | Oil & Gas Operator | Feb 2007 |
| 225 | Huber Energy Panhandle LP | Houston, TX 77079 | Oil & Gas Operator | Oct 2005 |
| 226 | Huber J M Corp | Edison, NJ 08837 | Oil & Gas Operator | May 2025 |
| 227 | Hughes, Dan A. Company | Beeville, TX 78104 | Oil & Gas Operator | May 2006 |
| 228 | Hughes, Dan A. Company, L.P. | Beeville, TX 78104 | Oil & Gas Operator | May 2025 |
| 229 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | May 2025 |
| 230 | Hunter & Hedrick Production, Inc | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Dec 1995 |
| 231 | Hurd Enterprises, LTD. | San Antonio, TX 78209 | Oil & Gas Operator | May 2025 |
| 232 | Hyquest Energy, Inc. | Midland, TX 79710 | Oil & Gas Operator | Mar 2015 |
| 233 | I.T. Corporation | Arlington, TX 76016 | Oil & Gas Operator | May 2025 |
| 234 | Imagery Exploration, Inc. | Dallas, TX 75380 | Oil & Gas Operator | May 2025 |
| 235 | Inexco Oil Company | Houston, TX 77210 | Oil & Gas Operator | Mar 2013 |
| 236 | Inland Ocean, Inc. | San Antonio, TX 78205 | Oil & Gas Operator | May 2025 |
| 237 | Intercity Management Corp. | Corpus Chrsti, TX 78412 | Oil & Gas Operator | May 2025 |
| 238 | Intercoastal Energy, Inc. | Houston, TX 77055 | Oil & Gas Operator | Aug 2003 |
| 239 | Ipr USA Corp. | Irving, TX 75039 | Oil & Gas Operator | Jun 2009 |
| 240 | Iv L.C. | San Antonio, TX 78209 | Oil & Gas Operator | May 2025 |
| 241 | J G Oil & Gas | Albany, TX 76430 | Oil & Gas Operator | May 2025 |
| 242 | Jackson Energy Development, Inc. | Cedar Park, TX 78613 | Oil & Gas Operator | May 2025 |
| 243 | Jaco Production Company | Bakersfield, CA 93380 | Oil Operator | Feb 2025 |
| 244 | Jennings Exploration Company | Beeville, TX 78102 | Oil & Gas Operator | Feb 2024 |
| 245 | Johnson, William D. | Fort Worth, TX 76116 | Oil & Gas Operator | Mar 2008 |
| 246 | JTB Oil Company, Inc. | Refugio, TX 78377 | Oil & Gas Operator | May 2025 |
| 247 | Jura Energy Operating LLC | Houston, TX 77024 | Oil & Gas Operator | Jun 2023 |
| 248 | K-B Exploration Co. | Houston, TX 77057 | Oil & Gas Operator | May 2025 |
| 249 | Kaiser-Francis Oil Company | Tulsa, OK 74121 | Oil & Gas Operator | May 2025 |
| 250 | Kaler Energy Corp. | Boerne, TX 78006 | Oil & Gas Operator | May 2025 |
| 251 | KC Resources Inc | Snowmass VLG., CO 81615 | Oil & Gas Operator | Feb 2025 |
| 252 | Kebo Oil & Gas, Inc. | Portland, TX 78374 | Oil & Gas Operator | May 2025 |
| 253 | Keen Operating Company, Inc. | Austin, TX 78705 | Oil & Gas Operator | Aug 2001 |
| 254 | Keene, Roy J. Jr. | Sugar Land, TX 77498 | Oil & Gas Operator | Jun 2016 |
| 255 | Kemco Oil | Alice, TX 78332 | Oil & Gas Operator | Aug 2009 |
| 256 | Ken Petroleum Corporation | Dallas, TX 75206 | Oil & Gas Operator | Feb 2019 |
| 257 | Killam Oil Co., LTD. | Laredo, TX 78042 | Oil & Gas Operator | May 2025 |
| 258 | Killam Oil Company | Laredo, TX 78042 | Oil & Gas Operator | Mar 1994 |
| 259 | Kimbell Oil Company Of Texas | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2025 |
| 260 | Kinder Morgan Tejas Pipeline LLC | Houston, TX 77002 | Oil & Gas Operator | May 2025 |
| 261 | Kingfish Gathering LLC | Lago VIsta, TX 78645 | Oil & Gas Operator | May 2025 |
| 262 | Kriken Oil & Gas | Corpus Chrsti, TX 78426 | Oil & Gas Operator | Jul 2005 |
| 263 | Kriken Oil & Gas, Inc. | Corpus Chrsti, TX 78426 | Oil & Gas Operator | May 2025 |
| 264 | L & F Drilling Co., Inc. (1) | Corpus Chrsti, TX 78479 | Oil & Gas Operator | May 2025 |
| 265 | L & R Petroleum | Kilgore, TX 75663 | Oil & Gas Operator | May 2025 |
| 266 | Lamar Oil & Gas, Inc. | Rockport, TX 78381 | Oil & Gas Operator | May 2025 |
| 267 | Lampert Exploration Corporation | Dallas, TX 75206 | Oil & Gas Operator | Mar 2008 |
| 268 | Langham Petroleum Expl. Corp. | Houston, TX 77056 | Oil & Gas Operator | Dec 2009 |
| 269 | Laroca Resources, LTD | Austin, TX 78709 | Oil & Gas Operator | May 2025 |
| 270 | Lawbar Petroleum, Inc. | Tuleta, TX 78162 | Oil & Gas Operator | Aug 2003 |
| 271 | Legacy Oil & Gas, Inc. | Portland, TX 78374 | Oil & Gas Operator | May 2025 |
| 272 | Limestone Oil & Gas Co. | Wichita Falls, TX 76302 | Oil & Gas Operator | Jul 2002 |
| 273 | Little, Lou Operating Co., Inc. | Portland, TX 78374 | Oil & Gas Operator | Sep 2014 |
| 274 | Lone Tree Oil & Gas LLC | Greenwood VLG, CO 80111 | Oil & Gas Operator | May 2025 |
| 275 | Lucros International Corporation | Van Buren, AR 72956 | Oil & Gas Operator | May 2025 |
| 276 | Lundberg Oil Co. | Dallas, TX 75360 | Oil & Gas Operator | Jan 2003 |
| 277 | Lundberg Operating Corporation | Dallas, TX 75225 | Oil & Gas Operator | Oct 2002 |
| 278 | Lytle Creek Operating, Inc. | Abilene, TX 79606 | Oil & Gas Operator | May 2025 |
| 279 | M & S Exploration | El Campo, TX 77437 | Oil & Gas Operator | May 2025 |
| 280 | M. J. G., Inc. | Alice, TX 78333 | Oil & Gas Operator | Jul 2010 |
| 281 | M. P. S. Prod. Co. | Houston, TX 77225 | Oil & Gas Operator | Dec 1996 |
| 282 | Magnum Engineering Company | Corpus Chrsti, TX 78401 | Oil & Gas Operator | May 2025 |
| 283 | Magnum Producing & Operating Co. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jan 2004 |
| 284 | Magnum Producing, LP | Corpus Chrsti, TX 78401 | Oil & Gas Operator | May 2025 |
| 285 | Mantle Oil & Gas, LLC | Friendswood, TX 77546 | Oil & Gas Operator | May 2025 |
| 286 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Mar 2025 |
| 287 | Mark IV Energy | San Antonio, TX 78213 | Oil & Gas Operator | Apr 1993 |
| 288 | Marquee Corporation | Houston, TX 77024 | Oil & Gas Operator | May 2025 |
| 289 | Marwell Petroleum LTD Partnrship | Houston, TX 77027 | Oil & Gas Operator | May 2025 |
| 290 | Marwell Petroleum, Inc. | Houston, TX 77057 | Oil & Gas Operator | Apr 2006 |
| 291 | Matador Operating Company | Dallas, TX 75240 | Oil & Gas Operator | Jul 2003 |
| 292 | Mayfield Energy, LLC | Austin, TX 78732 | Oil & Gas Operator | May 2025 |
| 293 | McDonald & Johnson Resources,LLC | Cypress, TX 77429 | Oil & Gas Operator | Dec 2010 |
| 294 | McDonnold Operating, Inc. | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 295 | McGowan Working Partners, Inc. | Jackson, MS 39296 | Oil & Gas Operator | May 2025 |
| 296 | McGuffin, Joe S. Inc. | Mathis, TX 78368 | Gas Operator | May 2025 |
| 297 | McLeod, George L. Inc. | Houston, TX 77079 | Oil & Gas Operator | Sep 2002 |
| 298 | Medders Oil Company | Wichita Falls, TX 76308 | Oil & Gas Operator | May 2025 |
| 299 | Meeker & Company | Fort Worth, TX 76102 | Oil & Gas Operator | May 2025 |
| 300 | Mego Resources, LLC | Taft, TX 78390 | Oil & Gas Operator | May 2025 |