| 301 | Hanley Petroleum Inc. | Midland, TX 79701 | Oil & Gas Operator | Oct 2017 |
| 302 | Hanson Corporation | New Braunfels, TX 78132 | Oil & Gas Operator | Mar 2008 |
| 303 | Hat Oil & Gas, Inc. | Slaton, TX 79364 | Oil & Gas Operator | Feb 2002 |
| 304 | Haylan Oil Company | Midland, TX 79710 | Oil & Gas Operator | Jan 2000 |
| 305 | Headington Oil Company | Dallas, TX 75231 | Oil & Gas Operator | Dec 2016 |
| 306 | Headline Resources, Inc. | Richardson, TX 75080 | Oil & Gas Operator | Aug 1997 |
| 307 | Helms Oil & Gas, LLC | Midland, TX 79710 | Oil & Gas Operator | Apr 2025 |
| 308 | Henderson, Bryan, Co. | Dallas, TX 75225 | Oil & Gas Operator | Apr 2025 |
| 309 | Hendrix, John H. Corporation | Midland, TX 79705 | Oil & Gas Operator | Sep 2018 |
| 310 | Henry Petroleum Corp. | Midland, TX 79703 | Oil & Gas Operator | Mar 2001 |
| 311 | Henry Petroleum LP | Midland, TX 79701 | Oil & Gas Operator | Dec 2008 |
| 312 | Henry Resources LLC | Midland, TX 79703 | Oil & Gas Operator | Apr 2025 |
| 313 | Herbig Oil & Gas Co. | Midland, TX 79701 | Oil & Gas Operator | Apr 2025 |
| 314 | Herbig, J F | Midland, TX 79701 | Oil & Gas Operator | Mar 1998 |
| 315 | Herricks Oil Co. | San Angelo, TX 76906 | Oil & Gas Operator | Jan 2010 |
| 316 | Hibernia Resources III, LLC | Houston, TX 77056 | Oil & Gas Operator | Nov 2023 |
| 317 | Highland Production Company | Midland, TX 79701 | Oil & Gas Operator | Mar 1996 |
| 318 | Highmark Energy Operating, LLC | Dallas, TX 75222 | Oil & Gas Operator | Apr 2025 |
| 319 | Hillin Prod. Co. | Odessa, TX 79760 | Oil & Gas Operator | Apr 2002 |
| 320 | Hillside Oil & Gas, LLC | Midland, TX 79708 | Oil & Gas Operator | Apr 2016 |
| 321 | HK Energy Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | May 2023 |
| 322 | Home Petroleum Corp | Victoria, TX 77902 | Oil & Gas Operator | Apr 2025 |
| 323 | Honeck Oil Company | Austin, TX 78716 | Oil & Gas Operator | Mar 2008 |
| 324 | Honeck Oil Company, LP | Austin, TX 78716 | Oil & Gas Operator | Dec 2010 |
| 325 | Horizon Oil & Gas Co. | Dallas, TX 75221 | Oil & Gas Operator | Jan 2005 |
| 326 | HPPC, Inc. | Midland, TX 79701 | Oil & Gas Operator | Feb 2023 |
| 327 | Huber J M Corp | Edison, NJ 08837 | Oil & Gas Operator | Apr 2025 |
| 328 | Huff, Jack | Midland, TX 79710 | Oil & Gas Operator | Dec 2004 |
| 329 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Apr 2025 |
| 330 | Huntington Energy LLC | Nichols Hill, OK 73116 | Oil & Gas Operator | Apr 2025 |
| 331 | Hurst Oil & Gas, Inc. | Hillsboro, TX 76645 | Oil & Gas Operator | Dec 2024 |
| 332 | Hydrocarbon Management, Inc. | San Antonio, TX 78216 | Oil & Gas Operator | Dec 1996 |
| 333 | Hyquest Energy, Inc. | Midland, TX 79710 | Oil & Gas Operator | Mar 2015 |
| 334 | Ibex Resources Operating LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Jun 2007 |
| 335 | Ibex Resources, LLC | Austin, TX 78751 | Oil & Gas Operator | Jul 1999 |
| 336 | Ica Energy Operating, L.L.C. | Odessa, TX 79760 | Oil & Gas Operator | Apr 2025 |
| 337 | Imperial Gas Resources LLC | Austin, TX 78701 | Oil & Gas Operator | Apr 2025 |
| 338 | Imperial Oil Company | Houston, TX 77073 | Oil & Gas Operator | Oct 2004 |
| 339 | Imperial Operating Co., L.L.C. | Midland, TX 79701 | Oil Operator | Sep 2023 |
| 340 | Incline Energy | Midland, TX 79710 | Oil & Gas Operator | Apr 2025 |
| 341 | Independence Resources MGMT, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Mar 2021 |
| 342 | Infinity Hydrocarbons LLC | Houston, TX 77079 | Oil & Gas Operator | Aug 2022 |
| 343 | Ip Petroleum Company, Inc. | Houston, TX 77210 | Oil & Gas Operator | Mar 2008 |
| 344 | Ipt Oil Company | Evansville, IN 47706 | Oil & Gas Operator | Apr 2025 |
| 345 | Iskandia Energy Operating, Inc. | Houston, TX 77002 | Oil & Gas Operator | Apr 2025 |
| 346 | J-E Production, Inc. | Midland, TX 79708 | Oil & Gas Operator | Mar 2008 |
| 347 | Jamex, Inc. | Lewisville, TX 75067 | Oil & Gas Operator | Apr 2025 |
| 348 | Jasper Resources, Inc. | Midland, TX 79701 | Oil & Gas Operator | Oct 1996 |
| 349 | Jay Management Company LLC | Houston, TX 77057 | Oil & Gas Operator | Apr 2025 |
| 350 | Jetta Operating Company Inc | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2025 |
| 351 | Jones, Charles E., Jr. | Odessa, TX 79760 | Oil & Gas Operator | Jul 2013 |
| 352 | Jones, Johnny G. | Midland, TX 79708 | Oil & Gas Operator | Feb 2000 |
| 353 | JTL Operating Co Inc | Katy, TX 77450 | Oil & Gas Operator | Apr 2025 |
| 354 | Jurassic Exploration, Inc. | Longview, TX 75601 | Oil & Gas Operator | Apr 2025 |
| 355 | Jva Operating Company | Midland, TX 79710 | Oil & Gas Operator | Oct 2021 |
| 356 | K.M.A. Operating, Inc. | Graham, TX 76450 | Oil & Gas Operator | Aug 2003 |
| 357 | K.W.A., Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 2025 |
| 358 | K3 Productions LLC | Houston, TX 77269 | Oil & Gas Operator | Apr 2025 |
| 359 | Kaiser-Francis Oil Company | Tulsa, OK 74121 | Oil & Gas Operator | Apr 2025 |
| 360 | Karico GP, LLC | Midland, TX 79705 | Oil & Gas Operator | Apr 2025 |
| 361 | Kelt Oil & Gas, Inc. | Torrance, CA 90503 | Oil & Gas Operator | Dec 2003 |
| 362 | Kem Energy, Inc. | Katy, TX 77450 | Oil & Gas Operator | Apr 2025 |
| 363 | Kenworthy Oil Company | Midland, TX 79710 | Oil & Gas Operator | Apr 2025 |
| 364 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | Jan 2025 |
| 365 | Kerry Oil & Gas, Inc. | Midland, TX 79702 | Oil & Gas Operator | Jan 2004 |
| 366 | Key Energy Of Colorado, Inc. | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2016 |
| 367 | Keystone Petroleum GP LLC | Irving, TX 75039 | Oil & Gas Operator | May 2012 |
| 368 | Kimbell Oil Company Of Texas | Fort Worth, TX 76102 | Oil & Gas Operator | Feb 2025 |
| 369 | Kinder Morgan Production Co LLC | Midland, TX 79705 | Oil & Gas Operator | Apr 2025 |
| 370 | King Operating Corporation | Fort Worth, TX 76147 | Oil & Gas Operator | Apr 2025 |
| 371 | Kinney Incorporated | Andrews, TX 79714 | Oil & Gas Operator | Apr 2025 |
| 372 | Kneupper Oil, LLC | MC Camey, TX 79752 | Oil & Gas Operator | Apr 2025 |
| 373 | L & L Resources, Inc. | Hays, KS 67601 | Oil Operator | Mar 1986 |
| 374 | La VIda Energy Corporation | Midland, TX 79702 | Oil & Gas Operator | Apr 1993 |
| 375 | Laguna Petroleum Corporation | Houston, TX 77046 | Oil & Gas Operator | Apr 2025 |
| 376 | Large Operating LLC | Stinnett, TX 79083 | Oil & Gas Operator | Apr 2025 |
| 377 | Lario Oil & Gas Company | Odessa, TX 79762 | Oil & Gas Operator | Apr 2025 |
| 378 | Last Mile Production, LLC | Austin, TX 78746 | Oil & Gas Operator | Apr 2025 |
| 379 | Latex Petroleum Corp. | Houston, TX 77090 | Oil & Gas Operator | Aug 2012 |
| 380 | Latigo Petroleum Texas, LP | Houston, TX 77002 | Oil & Gas Operator | Feb 2009 |
| 381 | Lawson Petroleum Co. | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2009 |
| 382 | Legacy Reserves Operating LP | Denver, CO 80201 | Oil & Gas Operator | Apr 2025 |
| 383 | Legado Permian, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | May 2013 |
| 384 | Limark Corporation | Midland, TX 79702 | Oil & Gas Operator | Dec 2003 |
| 385 | Linn Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Jan 2019 |
| 386 | Linn Operating, Inc. | Houston, TX 77002 | Oil & Gas Operator | May 2017 |
| 387 | Llano Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2025 |
| 388 | LNH Oil Company | Midland, TX 79708 | Oil & Gas Operator | Jan 2006 |
| 389 | Lomak Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Aug 1998 |
| 390 | Lone Star Oil & Gas | Midland, TX 79702 | Oil & Gas Operator | Apr 2025 |
| 391 | Longhorn Service & Drilling Co. | Kermit, TX 79745 | Oil & Gas Operator | Jun 2019 |
| 392 | Losure Pet. Co. | Borger, TX 79008 | Oil & Gas Operator | Apr 2014 |
| 393 | Losure, Ken | Borger, TX 79008 | Oil & Gas Operator | Apr 2025 |
| 394 | Lynx Energy Company, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Mar 2008 |
| 395 | Lynx Oil Co., Inc. | Denton, TX 76207 | Oil & Gas Operator | Sep 2003 |
| 396 | Lynx Operating Co., Inc. | Dallas, TX 75206 | Oil & Gas Operator | Apr 2025 |
| 397 | Lynx Petroleum Consultants Inc. | Hobbs, NM 88241 | Oil & Gas Operator | Feb 2024 |
| 398 | LZB Energy, LLC | Austin, TX 78737 | Gas Operator | Jul 2020 |
| 399 | LZS Corporation | Tulsa, OK 74105 | Oil & Gas Operator | Jan 2007 |
| 400 | M & J Energy, Inc. | Breckenridge, CO 80424 | Oil & Gas Operator | Apr 2025 |