| 301 | Hanson Corporation | New Braunfels, TX 78132 | Oil & Gas Operator | Mar 2008 |
| 302 | Harrison Interests, LTD. | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 303 | Hawkeye Transmission Company | Dallas, TX 75244 | Oil & Gas Operator | Jun 2000 |
| 304 | Headington Oil Company | Dallas, TX 75231 | Oil & Gas Operator | Dec 2016 |
| 305 | Headington Oil Company LLC | Dallas, TX 75204 | Oil & Gas Operator | Apr 2016 |
| 306 | Headington Oil Company, L.P. | Dallas, TX 75231 | Oil & Gas Operator | Mar 2008 |
| 307 | Headline Resources, Inc. | Richardson, TX 75080 | Oil & Gas Operator | Aug 1997 |
| 308 | Hebron Pipeline | San Antonio, TX 78209 | Oil & Gas Operator | Oct 2025 |
| 309 | Helmerich & Payne, Inc. | Tulsa, OK 74114 | Oil & Gas Operator | Jun 2025 |
| 310 | Helms Oil & Gas, LLC | Midland, TX 79710 | Oil & Gas Operator | Oct 2025 |
| 311 | Henderson & Erickson, Inc. | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 312 | Hendrix, John H. Corporation | Midland, TX 79705 | Oil & Gas Operator | Sep 2018 |
| 313 | Henry Petroleum Corp. | Midland, TX 79703 | Oil & Gas Operator | Mar 2001 |
| 314 | Henry Petroleum LLC | Flower Mound, TX 75028 | Oil & Gas Operator | Oct 2025 |
| 315 | Henry Petroleum LP | Midland, TX 79701 | Oil & Gas Operator | Dec 2008 |
| 316 | Henry Resources LLC | Midland, TX 79703 | Oil & Gas Operator | Oct 2025 |
| 317 | Hexp Operating, LLC | Midland, TX 79705 | Oil & Gas Operator | Oct 2025 |
| 318 | Highground, Inc. | Abilene, TX 79605 | Oil & Gas Operator | Oct 2025 |
| 319 | Highland Production Company | Midland, TX 79701 | Oil & Gas Operator | Mar 1996 |
| 320 | Highmount Expl & Prod Texas LLC | Houston, TX 77002 | Oil & Gas Operator | Sep 2014 |
| 321 | Hillin, T. A. | Kerrville, TX 78028 | Oil & Gas Operator | Aug 2020 |
| 322 | HMH Operators, Inc. | Midland, TX 79701 | Oil & Gas Operator | Aug 2003 |
| 323 | Hobbs Energy Corporation | San Angelo, TX 76904 | Oil & Gas Operator | Mar 2008 |
| 324 | Holly Petroleum, Inc. | Midland, TX 79702 | Oil & Gas Operator | Nov 2008 |
| 325 | Home Petroleum Corp | Victoria, TX 77902 | Oil & Gas Operator | Oct 2025 |
| 326 | Hoover Petroleum Company, LLC | Midland, TX 79701 | Oil Operator | Oct 2025 |
| 327 | HRB Operating Company, Inc. | Bridgeport, TX 76426 | Oil & Gas Operator | Oct 2025 |
| 328 | Hubbard Operating | Ozona, TX 76943 | Gas Operator | Oct 2025 |
| 329 | Huber J M Corp | Edison, NJ 08837 | Oil & Gas Operator | Oct 2025 |
| 330 | Huff, Jack | Midland, TX 79710 | Oil & Gas Operator | Dec 2004 |
| 331 | Huffman, H. L., LTD. | Fort Worth, TX 76113 | Oil & Gas Operator | Sep 1994 |
| 332 | Hughes, Bob Oil Company | San Angelo, TX 76901 | Oil & Gas Operator | Jul 2011 |
| 333 | Hunt Petroleum Corporation | Dallas, TX 75201 | Oil & Gas Operator | Nov 2008 |
| 334 | I.T. Corporation | Arlington, TX 76016 | Oil & Gas Operator | Oct 2025 |
| 335 | Ica Energy Operating, L.L.C. | Odessa, TX 79760 | Oil & Gas Operator | Oct 2025 |
| 336 | Incline Energy | Midland, TX 79710 | Oil & Gas Operator | Oct 2025 |
| 337 | Ingram, J. Oil & Gas, Inc. | Plano, TX 75074 | Oil & Gas Operator | Oct 2025 |
| 338 | Ip Petroleum Company, Inc. | Houston, TX 77210 | Oil & Gas Operator | Mar 2008 |
| 339 | Iron Orchard Operating LLC | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 340 | Isom Energy, Inc. | San Angelo, TX 76904 | Oil & Gas Operator | May 2018 |
| 341 | J & J Services Company | San Angelo, TX 76904 | Oil & Gas Operator | Oct 2025 |
| 342 | J Rico Oil, LLC | Henderson, NV 89074 | Oil & Gas Operator | Oct 2025 |
| 343 | J. C. Oil Company | Odessa, TX 79766 | Oil & Gas Operator | Mar 2015 |
| 344 | J. D. Gas, Inc. | Stephenville, TX 76401 | Oil & Gas Operator | Oct 2025 |
| 345 | J.P. Oil Company, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 346 | Jay Management Company LLC | Houston, TX 77057 | Oil & Gas Operator | Oct 2025 |
| 347 | Jay Resources Corporation | Houston, TX 77010 | Oil & Gas Operator | Feb 1998 |
| 348 | JC Enterprises | Andrews, TX 79714 | Oil & Gas Operator | Jun 2012 |
| 349 | Jeter Drilling Production | Del Rio, TX 78840 | Oil & Gas Operator | Oct 2025 |
| 350 | Jilpetco, Inc. | Fort Worth, TX 76121 | Oil & Gas Operator | Oct 2025 |
| 351 | Jim-Bob Oil Company | San Angelo, TX 76901 | Oil & Gas Operator | Dec 2003 |
| 352 | JMK Petroleum Corp. | Dallas, TX 75251 | Oil & Gas Operator | Jun 2006 |
| 353 | JMW Resources, Inc. | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 354 | Johnson & Lindley, Inc. | Houston, TX 77227 | Oil & Gas Operator | May 2013 |
| 355 | Jones, Johnny G. | Midland, TX 79708 | Oil & Gas Operator | Feb 2000 |
| 356 | Josey Oil Company | Houston, TX 77019 | Oil & Gas Operator | Jul 2006 |
| 357 | JTL Operating Co Inc | Katy, TX 77450 | Oil & Gas Operator | Oct 2025 |
| 358 | K & E Oil & Gas Co. | Bayfield, CO 81122 | Oil & Gas Operator | Oct 2008 |
| 359 | K & K Oil Co. | Corsicana, TX 75109 | Oil & Gas Operator | Oct 2025 |
| 360 | Kaiser-Francis Oil Company | Tulsa, OK 74121 | Oil & Gas Operator | Oct 2025 |
| 361 | Katsco Energy, Inc. | Round Rock, TX 78664 | Oil & Gas Operator | Oct 2025 |
| 362 | KDM Production Co | Ozona, TX 76943 | Oil & Gas Operator | Oct 2025 |
| 363 | Kebo Oil & Gas, Inc. | Portland, TX 78374 | Oil & Gas Operator | Oct 2025 |
| 364 | Kern Co. | Houston, TX 77095 | Oil & Gas Operator | Jan 2021 |
| 365 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | May 2025 |
| 366 | Kerr-McGee Oil & Gas Onshore LP | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |
| 367 | Kestrel Resources, Inc. | Dallas, TX 75204 | Oil & Gas Operator | Jan 2017 |
| 368 | Kidd Johnson Oil & Gas | San Angelo, TX 76904 | Oil & Gas Operator | Feb 2013 |
| 369 | Kidd Johnson Oil & Gas, LLC | San Angelo, TX 76904 | Oil & Gas Operator | Oct 2025 |
| 370 | Kilmarnock Oil Company, Inc. | Corsicana, TX 75110 | Oil & Gas Operator | Oct 2025 |
| 371 | Kimbrough Engineering Co, LLC | New Braunfels, TX 78132 | Oil & Gas Operator | Dec 2014 |
| 372 | Kimbrough, D. E. | Iraan, TX 79744 | Oil & Gas Operator | Oct 2025 |
| 373 | Kimsey, Roy E., Jr. | Midland, TX 79701 | Oil & Gas Operator | May 2018 |
| 374 | Kindee Oil & Gas Texas, LLC | Houston, TX 77084 | Oil & Gas Operator | Apr 2016 |
| 375 | Kinder Morgan Production Co LLC | Midland, TX 79705 | Oil & Gas Operator | Oct 2025 |
| 376 | Kinder Morgan Production Co LP | Midland, TX 79701 | Oil & Gas Operator | Jul 2007 |
| 377 | Kinder Morgan Sacroc LP | Snyder, TX 79549 | Oil & Gas Operator | Dec 2003 |
| 378 | Kindred Petroleum Company | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 379 | Kinney Incorporated | Andrews, TX 79714 | Oil & Gas Operator | Oct 2025 |
| 380 | Klassen Energy, Inc. | Cisco, TX 76437 | Oil & Gas Operator | Oct 2025 |
| 381 | Kneupper Oil, LLC | MC Camey, TX 79752 | Oil & Gas Operator | Oct 2025 |
| 382 | Koch Midstream Services Company | Wichita, KS 67201 | Oil & Gas Operator | Oct 2000 |
| 383 | Kodiak Productions LTD | Big Lake, TX 76932 | Oil & Gas Operator | Mar 2014 |
| 384 | Ksabe Energy Partners, LLC | Oklahoma City, OK 73106 | Oil Operator | Oct 2025 |
| 385 | Kstone Energy, LLC | Oklahoma City, OK 73106 | Oil Operator | Oct 2025 |
| 386 | L & D, Inc. | San Angelo, TX 76906 | Oil & Gas Operator | May 2019 |
| 387 | L & M Operating, Inc. | Big Lake, TX 76932 | Oil & Gas Operator | Oct 2025 |
| 388 | L & R Energy Corporation | Spearman, TX 79081 | Oil & Gas Operator | Nov 2014 |
| 389 | Lackey, William H. Oil And Gas | Shawnee, OK 74804 | Oil & Gas Operator | Feb 2024 |
| 390 | Laguna Petroleum Corporation | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |
| 391 | Lamb, James L., Jr. | Austin, TX 78750 | Oil & Gas Operator | Mar 2016 |
| 392 | Landrick O & G Operating, LLC | Midland, TX 79705 | Oil & Gas Operator | Oct 2025 |
| 393 | Lankford Oil Co. | Weatherford, TX 76086 | Oil & Gas Operator | Jul 1999 |
| 394 | Largo Oil Company | Longview, TX 75606 | Oil & Gas Operator | Oct 2025 |
| 395 | Lariat Resources, LLC | Fort Worth, TX 76109 | Oil & Gas Operator | May 2022 |
| 396 | Lario Oil & Gas Company | Odessa, TX 79762 | Oil & Gas Operator | Oct 2025 |
| 397 | Larron Energy Corporation | New Braunfels, TX 78132 | Oil & Gas Operator | Mar 2015 |
| 398 | Las Animas Production Company | Midland, TX 79705 | Oil & Gas Operator | Mar 1995 |
| 399 | Last Dollar LLC | Big Lake, TX 76932 | Oil & Gas Operator | Oct 2025 |
| 400 | Latex Petroleum Corp. | Houston, TX 77090 | Oil & Gas Operator | Aug 2012 |