| 201 | Sullivan, Hollis R. Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Feb 2009 |
| 202 | Sundance Resources, Inc. | Rio VIsta, TX 76093 | Oil & Gas Operator | Mar 2012 |
| 203 | Targa Midstream Services LLC | Houston, TX 77002 | Oil Operator | Mar 2023 |
| 204 | TDC Engineering, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Apr 2024 |
| 205 | Tejas Western Corp. | Granbury, TX 76048 | Oil & Gas Operator | Jul 2018 |
| 206 | Teleo Operating, LLC | Dallas, TX 75219 | Oil & Gas Operator | Apr 2009 |
| 207 | Tep Barnett USA, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2024 |
| 208 | Texas Independent Oil Co., LLC | Argyle, TX 76226 | Oil & Gas Operator | Apr 2024 |
| 209 | Texcel Exploration, Inc. | Colorado SPGS, CO 80960 | Oil & Gas Operator | Apr 2024 |
| 210 | Texxol Operating Company, Inc. | Fort Worth, TX 76108 | Oil & Gas Operator | Apr 2024 |
| 211 | Thompson, J. Cleo | Dallas, TX 75201 | Oil & Gas Operator | Apr 2024 |
| 212 | Tidewater Resources Corporation | Memphis, TN 38138 | Gas Operator | Apr 2024 |
| 213 | Titan Operating, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Jun 2012 |
| 214 | Tracker Mineral | Clyde, TX 79510 | Oil & Gas Operator | Apr 2024 |
| 215 | Trinity River Energy Oper, LLC | Houston, TX 77008 | Oil & Gas Operator | May 2018 |
| 216 | Trio Consulting & Management,LLC | Wichita Falls, TX 76307 | Oil & Gas Operator | Apr 2024 |
| 217 | Trio Operating Company, Inc. | Wichita Falls, TX 76307 | Oil & Gas Operator | Apr 2006 |
| 218 | Triple G Well Service, Inc. | Muenster, TX 76252 | Oil & Gas Operator | Apr 2024 |
| 219 | Txu Gas Company | Dallas, TX 75201 | Oil & Gas Operator | Sep 2004 |
| 220 | Txu Lone Star Pipeline | Dallas, TX 75201 | Oil & Gas Operator | Oct 2003 |
| 221 | Universal Resources Corp. | Salt Lake Cty, UT 84145 | Oil & Gas Operator | Jan 2000 |
| 222 | Upland Operating, LLC | Dallas, TX 75226 | Oil & Gas Operator | Apr 2024 |
| 223 | Upp Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Apr 2024 |
| 224 | Upstream Properties, LLC | Southlake, TX 76092 | Oil & Gas Operator | Apr 2024 |
| 225 | Van Tol Oil | Sanger, TX 76266 | Oil & Gas Operator | Apr 2024 |
| 226 | Vantage Fort Worth Energy LLC | Pittsburgh, PA 15222 | Oil & Gas Operator | Oct 2017 |
| 227 | Vicars Oil & Gas Corporation | Bowie, TX 76230 | Gas Operator | Jul 2010 |
| 228 | Voth Operating, Inc. | Muenster, TX 76252 | Oil & Gas Operator | Oct 2005 |
| 229 | Wehunt Oil Company, Inc. | Dallas, TX 75376 | Oil & Gas Operator | Nov 2002 |
| 230 | Western Chief Oil & Gas Company | Graham, TX 76450 | Oil & Gas Operator | Jul 2009 |
| 231 | Western Chief Operating, L.L.C. | Graham, TX 76450 | Oil & Gas Operator | Apr 2024 |
| 232 | Westside Energy Op. Co., LP | Oklahoma City, OK 73142 | Oil & Gas Operator | Jun 2008 |
| 233 | Williams Prod. Gulf Coast, L.P. | Benbrook, TX 76126 | Oil & Gas Operator | Jan 2012 |
| 234 | Winchester Production Company | Shreveport, LA 71129 | Oil & Gas Operator | Nov 2008 |
| 235 | Winfield Operating Company | Dallas, TX 75214 | Oil & Gas Operator | Apr 2024 |
| 236 | Wise Production Company | Bowie, TX 76230 | Oil & Gas Operator | Apr 2024 |
| 237 | Wolsey Well Service, Inc. | Windthorst, TX 76389 | Oil & Gas Operator | Jul 2006 |
| 238 | Wolsey Well Service, L.P. | Bowie, TX 76230 | Oil & Gas Operator | Jun 2014 |
| 239 | WPX Energy Gulf Coast, LP | Benbrook, TX 76126 | Oil & Gas Operator | May 2012 |
| 240 | WT Fitts Operating | Bowie, TX 76230 | Oil & Gas Operator | Apr 2024 |
| 241 | Wy Woodland Operating, LLC | Covington, TX 76636 | Oil & Gas Operator | Apr 2024 |
| 242 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Apr 2024 |
| 243 | Xyz Oil, Inc. | Muenster, TX 76252 | Oil & Gas Operator | Apr 2024 |