| 1 | Tall Dune Resources, LLC | Boerne, TX 78006 | Oil & Gas Operator | Feb 2026 |
| 2 | Tamarack Energy Inc | Midland, TX 79701 | Oil & Gas Operator | Dec 2015 |
| 3 | TCC Royalty Corporation | Centennial, CO 80112 | Gas Operator | Sep 2005 |
| 4 | Tejas Gas Corp | | Oil & Gas Operator | Dec 1974 |
| 5 | Tenneco Oil Company | Oklahoma City, OK 73125 | Oil & Gas Operator | Nov 2025 |
| 6 | Terra Resources, Inc. | Casper, WY 82601 | Oil & Gas Operator | Jun 1990 |
| 7 | Teton Energy Co Inc | Denver, CO 80239 | Oil Operator | Dec 1983 |
| 8 | Texaco E & P Inc. | Houston, TX 77099 | Oil & Gas Operator | Feb 2026 |
| 9 | Texaco Inc | Kingfisher, OK 73750 | Oil & Gas Operator | Dec 2017 |
| 10 | Texaco Producing Inc. | Rock Springs, WY 82901 | Oil & Gas Operator | Dec 2000 |
| 11 | Texakoma Oil & Gas Corp | Dallas, TX 75240 | Oil & Gas Operator | Sep 2014 |
| 12 | Texas American Oil Corporation | Midland, TX 79701 | Oil & Gas Operator | Jan 2001 |
| 13 | Texas Eastern Skyline Oil | Houston, TX 77252 | Oil & Gas Operator | Jan 1987 |
| 14 | Texas Oil & Gas | Denver, CO 80264 | Oil & Gas Operator | Oct 1981 |
| 15 | Texoma Production Co | | Oil & Gas Operator | Jun 1986 |
| 16 | The Texas Company | FT Worth, TX 76101 | Oil & Gas Operator | Dec 2013 |
| 17 | Thompson, J C | Denver, CO 80237-2843 | Oil & Gas Operator | Jul 2005 |
| 18 | Three States Natural Gas | | Oil & Gas Operator | Mar 1976 |
| 19 | Thriftway Company | Farmington, NM 87401 | Oil & Gas Operator | Dec 1996 |
| 20 | Thurston Energy Operating | Vernal, UT 84078 | Oil & Gas Operator | Dec 2015 |
| 21 | Tidewater Co | | Oil & Gas Operator | Sep 1967 |
| 22 | Tiger Energy Operating, LLC | Los Angeles, CA 90025 | Oil & Gas Operator | Jan 2026 |
| 23 | Titan Energy Corp | Thomasville, AL 36784 | Oil & Gas Operator | Sep 2019 |
| 24 | Toc Oil Inc | Denver, CO 80202 | Oil & Gas Operator | Dec 2025 |
| 25 | Tola Production Company | Dallas, TX 75367 | Oil & Gas Operator | Feb 2026 |
| 26 | Toledo Mining Co | Irving, TX 75061 | Oil Operator | Dec 1989 |
| 27 | Tom Brown Inc | Denver, CO 80202 | Oil & Gas Operator | Dec 2004 |
| 28 | Total Minatome Corporation | Houston, TX 77210 | Oil & Gas Operator | Dec 1998 |
| 29 | Total Petroleum Inc | Houston, TX 77210 | Oil & Gas Operator | Feb 1998 |
| 30 | Transfuel Resources Co | Houston, TX 77215 | Oil & Gas Operator | Aug 2013 |
| 31 | Travis Oil Co | Los Angeles, CA 90024 | Oil Operator | Jan 1990 |
| 32 | Trend Oil Co | Petaluma, CA 94954 | Oil & Gas Operator | Feb 2017 |
| 33 | Triage Energy Corporation | Midland, TX 79708 | Oil & Gas Operator | Oct 2001 |
| 34 | Triangle Development Co | Mahtomedi, MN 55115 | Gas Operator | Feb 1982 |
| 35 | Tricentrol Resources Inc | Englewood, CO 80111 | Oil & Gas Operator | Jun 1984 |
| 36 | Trigg Drilling Company Inc | Oklahoma City, OK 73105 | Oil & Gas Operator | Jan 2013 |
| 37 | True Oil LLC | Casper, WY 82602 | Oil & Gas Operator | Dec 2025 |
| 38 | Twin Arrow Inc | Rangely, CO 81648 | Oil & Gas Operator | Sep 2009 |
| 39 | Txo Production Corp. | Ganado, TX 77962 | Oil & Gas Operator | Aug 2022 |