| 201 | Terry'S Roustabout Service, Inc. | Throckmorton, TX 76483 | Oil & Gas Operator | Oct 2002 |
| 202 | Terry, Lewis D. | Olney, TX 76374 | Oil & Gas Operator | Sep 1995 |
| 203 | Texcal Resources, Inc. | Plano, TX 75094 | Oil & Gas Operator | Apr 1994 |
| 204 | Three P Operating Company | Newcastle, TX 76372 | Oil & Gas Operator | Nov 2007 |
| 205 | Triangle Energy Co. | Pampa, TX 79066 | Oil & Gas Operator | Nov 2000 |
| 206 | Trio Operating Company, Inc. | Wichita Falls, TX 76307 | Oil & Gas Operator | Apr 2006 |
| 207 | United Operating Company | Olney, TX 76374 | Oil & Gas Operator | Aug 2003 |
| 208 | United Texas Petroleum Inc. | McKinney, TX 75070 | Oil & Gas Operator | May 2025 |
| 209 | Verdugo-Pablo Energy, LLC | Amarillo, TX 79105 | Oil & Gas Operator | Nov 2024 |
| 210 | W.T. Waggoner Estate, Inc. | Vernon, TX 76385 | Oil Operator | May 2025 |
| 211 | Waggoner, Ralph E. | Windthorst, TX 76389 | Oil & Gas Operator | Dec 2010 |
| 212 | Walsh & Watts Inc | Aledo, TX 76008 | Oil & Gas Operator | May 2025 |
| 213 | Walter Oil & Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | May 2025 |
| 214 | Wells Oilfield Services, Inc. | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 215 | Wes-Mor Drilling, Inc. | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 216 | Wharton Oil Co. | Vernon, TX 76384 | Oil & Gas Operator | Dec 2000 |
| 217 | Whiting Petroleum Corporation | Denver, CO 80290 | Oil & Gas Operator | Jan 2025 |
| 218 | Williams, Clayton Energy, Inc. | Houston, TX 77070 | Oil & Gas Operator | May 2025 |
| 219 | Willowbend Investments, Inc. | Wichita Falls, TX 76307 | Oil & Gas Operator | May 2025 |
| 220 | Wilson Operating Co. | Archer City, TX 76351 | Oil & Gas Operator | May 2025 |
| 221 | Wiser Oil Co | Denver, CO 80202 | Oil & Gas Operator | Dec 2023 |
| 222 | Wortham, E. H. | Holliday, TX 76366 | Oil & Gas Operator | Mar 2008 |
| 223 | Young Marshall R Oil Co | Fort Worth, TX 76107 | Oil & Gas Operator | Mar 2011 |