| 301 | Shell Western E&P Inc. | Houston, TX 77001 | Oil & Gas Operator | May 2011 |
| 302 | Sigmon Production Company, Inc. | Longview, TX 75608 | Oil & Gas Operator | Dec 2013 |
| 303 | Signal Oil Company, LLC | Kilgore, TX 75663 | Oil & Gas Operator | May 2025 |
| 304 | Silver Oak Operating, Inc. | Longview, TX 75601 | Oil & Gas Operator | Dec 2009 |
| 305 | Smal Energy Corp | Tyler, TX 75710 | Oil & Gas Operator | Oct 1995 |
| 306 | Sonoran Energy Inc. | Addison, TX 75001 | Oil & Gas Operator | May 2025 |
| 307 | Southwest Operating, Inc.-Tyler | Tyler, TX 75701 | Oil & Gas Operator | May 2025 |
| 308 | Spence, Ralph Oil Company, Inc. | Tyler, TX 75701 | Oil & Gas Operator | Jun 2023 |
| 309 | St. Mary Land & Exploration Co | Denver, CO 80201 | Oil & Gas Operator | Jun 2010 |
| 310 | Stewardship Resources | Roanoke, TX 76262 | Oil & Gas Operator | Jun 2022 |
| 311 | Stonebriar Oil LLC | Frisco, TX 75034 | Oil & Gas Operator | May 2025 |
| 312 | Stonewall Production Company Inc | Tyler, TX 75702 | Oil & Gas Operator | Aug 2009 |
| 313 | Strago Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Aug 1994 |
| 314 | Strand Energy, L.C. | Houston, TX 77002 | Oil & Gas Operator | May 2025 |
| 315 | Summit Resources MGMT., LLC. | Edmond, OK 73083 | Oil & Gas Operator | May 2025 |
| 316 | Sunland Production Company, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Mar 2025 |
| 317 | Tactical Operating Company, LLC | Houston, TX 77042 | Oil & Gas Operator | May 2025 |
| 318 | Tamarack Petroleum Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 319 | Tanos Exploration, LLC | Houston, TX 77010 | Oil & Gas Operator | Oct 2018 |
| 320 | Taubert & Steed | Wichita Falls, TX 76301 | Oil & Gas Operator | Aug 2001 |
| 321 | Teco Operating Company | Athens, TX 75751 | Oil & Gas Operator | Jun 2001 |
| 322 | Texeast Operating Co., Inc. | Farmers BRNCH, TX 75234 | Oil Operator | May 2025 |
| 323 | Texlan Oil Company, Inc. | Tyler, TX 75701 | Oil & Gas Operator | Nov 1994 |
| 324 | Texlan Oil Company, L.C. | Tyler, TX 75711 | Oil & Gas Operator | Aug 2003 |
| 325 | The Termo Company | Long Beach, CA 90801 | Oil & Gas Operator | Mar 2025 |
| 326 | Three D Submersible Pumps, Inc. | Heavener, OK 74937 | Oil & Gas Operator | Aug 2003 |
| 327 | Tola Production Company | Dallas, TX 75367 | Oil & Gas Operator | May 2025 |
| 328 | Tracy Production | Lindale, TX 75771 | Oil & Gas Operator | May 2025 |
| 329 | Trans-Texas Resources, Inc. | Tyler, TX 75702 | Oil & Gas Operator | Feb 1993 |
| 330 | Trek Resources, Inc. | Dallas, TX 75207 | Oil & Gas Operator | May 2025 |
| 331 | Tri-State Exploration & Prod Inc | Marshall, TX 75671 | Oil & Gas Operator | Aug 2003 |
| 332 | Tri-State Resources, Inc. | Tyler, TX 75711 | Oil & Gas Operator | Sep 2012 |
| 333 | Triple J Investments Inc | Longview, TX 75606 | Oil & Gas Operator | Feb 2023 |
| 334 | TTK Energy LLC | Kilgore, TX 75663 | Oil Operator | May 2025 |
| 335 | TXX Operating LLC | Shreveport, LA 71133 | Oil & Gas Operator | May 2025 |
| 336 | Ultra Oil & Gas, Inc. | Centerton, AR 72719 | Oil & Gas Operator | May 2025 |
| 337 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 338 | Union Pacific Resources Co. | Fort Worth, TX 76101 | Oil & Gas Operator | Sep 2002 |
| 339 | Upstream Properties, LLC | Southlake, TX 76092 | Oil & Gas Operator | May 2025 |
| 340 | Valence Operating Company | Kingwood, TX 77339 | Oil & Gas Operator | May 2025 |
| 341 | Vanco Oil & Gas Corp. | Abilene, TX 79604 | Oil & Gas Operator | May 2025 |
| 342 | Vanguard Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Feb 2021 |
| 343 | Vaughn Petroleum, Inc. | Dallas, TX 75219 | Oil & Gas Operator | May 2004 |
| 344 | Vintage Petroleum, Inc. | Houston, TX 77046 | Oil & Gas Operator | Feb 2025 |
| 345 | Viola Production Inc | Dallas, TX 75251 | Oil & Gas Operator | May 2025 |
| 346 | Vogo, Inc. | Blaine, WA 98230 | Oil Operator | May 2025 |
| 347 | Western Chief Operating, L.L.C. | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 348 | Weststar Oil & Gas Inc | Edmond, OK 73013 | Oil & Gas Operator | Mar 2025 |
| 349 | White Rock Exploration, Inc. | Tyler, TX 75701 | Oil & Gas Operator | Jul 2021 |
| 350 | Wilson - Owens Production Co. | Longview, TX 75601 | Oil & Gas Operator | Nov 1998 |
| 351 | Wilson, David A. | Longview, TX 75606 | Oil & Gas Operator | Mar 1997 |
| 352 | Winchester Production Company | Shreveport, LA 71129 | Oil & Gas Operator | Nov 2008 |
| 353 | Wisenbaker Production Company | Tyler, TX 75702 | Oil & Gas Operator | Oct 2011 |
| 354 | Wolverine Exploration Company | Houston, TX 77002 | Oil & Gas Operator | May 2019 |
| 355 | Woods Operating Co., Inc. | Shreveport, LA 71136 | Oil & Gas Operator | Dec 2020 |
| 356 | WTXR Operating (Texas), Inc. | Carrollton, TX 75007 | Oil Operator | May 2025 |
| 357 | Wynn-Crosby Operating, LTD. | Dallas, TX 75201 | Oil & Gas Operator | May 2025 |
| 358 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | May 2025 |