| 1301 | Trailhead Exploration, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2026 |
| 1302 | Traillour Oil Co. | | Oil & Gas Operator | Mar 1990 |
| 1303 | Trans Atlantic Ener Corp | Caldwell, OH 43724 | Oil & Gas Operator | Dec 1993 |
| 1304 | Trans Atlantic Resource Corp | Tulsa, OK 74136-5709 | Oil & Gas Operator | Nov 1998 |
| 1305 | Trans Energy, Inc. | St. Marys, WV 26170 | Oil & Gas Operator | Dec 2017 |
| 1306 | Trans Ocean Oil, Inc. | | Oil & Gas Operator | Sep 1980 |
| 1307 | Trans Pacific Oi | | Oil & Gas Operator | May 1995 |
| 1308 | Trans Pacific Oil Corporation | Wichita, KS 67202 | Oil & Gas Operator | Mar 2026 |
| 1309 | Trans Resource D | | Oil Operator | May 1991 |
| 1310 | Trans Terra Corp., International | Amarillo, TX 79159 | Oil & Gas Operator | Feb 2009 |
| 1311 | Trans Texas Minerals Company | Austin, TX 78714 | Oil & Gas Operator | Aug 1999 |
| 1312 | Trans-Gulf Petroleum Corp | | Oil & Gas Operator | Sep 1999 |
| 1313 | Trans-Pacific Oil & Gas Inc. | | Oil & Gas Operator | Mar 1982 |
| 1314 | Trans-Pecos Resources, Inc. | Houston, TX 77056 | Oil & Gas Operator | Jun 2026 |
| 1315 | Trans-Sabine Pipeline Corp | | Oil Operator | Mar 2009 |
| 1316 | Trans-Tex Operating LLC | Dallas, TX 75367 | Oil & Gas Operator | Jun 2026 |
| 1317 | Trans-Texas Energy Group LLC | Mineral Wells, TX 76068 | Oil & Gas Operator | Jul 2015 |
| 1318 | Trans-Western Exploration Inc | Dallas, TX 75240 | Oil & Gas Operator | Mar 1993 |
| 1319 | Trans-Western Operating Company | Golden, CO 80402 | Oil Operator | Nov 2025 |
| 1320 | Transamer Petro Corp | Pittsburgh, PA 15222-3510 | Gas Operator | Dec 1985 |
| 1321 | Transamerica Energy Corp. | Atlanta, GA 30356 | Oil & Gas Operator | Jun 2026 |
| 1322 | Transamerica Oil | | Oil & Gas Operator | Sep 1992 |
| 1323 | Transamerica Oil Corporation | Hutchinson, KS 67504 | Gas Operator | Mar 2025 |
| 1324 | Transamerican Energy/Toce Oil | | Oil & Gas Operator | Dec 1994 |
| 1325 | Transamerican Natural Gas Corp. | Houston, TX 77032 | Oil & Gas Operator | Aug 2000 |
| 1326 | Transamerican-Swepi-Toce Oil | | Oil & Gas Operator | Apr 1990 |
| 1327 | Transatlantic Expl LTD Dba Ravenna Oil | Beattyville, KY 41311 | Oil Operator | Dec 2023 |
| 1328 | Transatlantic Petr (USA) Corp. | Dallas, TX 75206 | Oil & Gas Operator | Jun 2026 |
| 1329 | Transco Exploration Company | | Oil & Gas Operator | Jul 1989 |
| 1330 | Transco Oil & Gas Inc. | | Gas Operator | Dec 1992 |
| 1331 | Transcoastal Operating LLC | Dallas, TX 75252-5646 | Oil & Gas Operator | Mar 2015 |
| 1332 | Transcontinental Company | Haltom City, TX 76148-4122 | Oil & Gas Operator | Feb 2026 |
| 1333 | Transcontinental Gas P/L Corp. | | Oil & Gas Operator | Dec 2009 |
| 1334 | Transcontinental Gas Pipeline Co LLC | | Oil Operator | Jan 2025 |
| 1335 | Transcontinental Minerals Corp. | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2008 |
| 1336 | Transcontinental Oil & Gas Inc | Aurora, OH 44202 | Oil & Gas Operator | Dec 2025 |
| 1337 | Transcontinental Oil Corp. | | Oil & Gas Operator | Sep 1985 |
| 1338 | Transcontinental Shale L.L.C. | Austin, TX 78717 | Oil & Gas Operator | Feb 2016 |
| 1339 | Transfuel Resources Co | Houston, TX 77215 | Oil & Gas Operator | Aug 2013 |
| 1340 | Transglobe Oil & Gas Corporation | Littleton, CO 801222710 | Oil & Gas Operator | Dec 1999 |
| 1341 | Transhorizon Energy Inc | Cheyenne, WY 82003 | Oil & Gas Operator | Jul 2023 |
| 1342 | Transit Energy Inc | North Lawrence, OH 44666 | Oil & Gas Operator | Dec 2025 |
| 1343 | Transoil, Inc. | Oklahoma City, OK 73129 | Oil & Gas Operator | Jun 2026 |
| 1344 | Transok LLC | Oklahoma City, OK 73124-0300 | Oil & Gas Operator | Jul 2020 |
| 1345 | Transpac Petroleum Inc. | | Oil & Gas Operator | Dec 1995 |
| 1346 | Transpacific Energy, LLC | Katy, TX 77450 | Oil & Gas Operator | Jun 2026 |
| 1347 | Transpetco I | Shreveport, LA 71101 | Oil & Gas Operator | May 2009 |
| 1348 | Transpetco Transport Company | Shreveport, LA 71101-5370 | Oil Operator | Jun 2008 |
| 1349 | Transtexas Gas Corporation | Houston, TX 77265 | Oil & Gas Operator | Aug 2005 |
| 1350 | Transworld Expl. & Prod., Inc. | | Oil & Gas Operator | Mar 2004 |
| 1351 | Transworld Systems Petroleum Inc | Denver, CO 80202 | Oil & Gas Operator | Sep 2025 |
| 1352 | Trap Rock Oil Company | Cambridge, MA 02138 | Oil & Gas Operator | Nov 2005 |
| 1353 | Trap Rock Oil, LTD. | Houston, TX 77005 | Oil & Gas Operator | Jun 2026 |
| 1354 | Trapp Oil Oper - | | Oil Operator | Aug 1989 |
| 1355 | Traton Operating Company | Kingwood, TX 77339 | Oil & Gas Operator | Mar 2019 |
| 1356 | Travco Well Servicing LLC | Okmulgee, OK 74447 | Oil Operator | Feb 2026 |
| 1357 | Travelers Oil Company | Amarillo, TX 79102 | Oil & Gas Operator | Jun 2026 |
| 1358 | Travell Energy, Inc | | Oil Operator | Dec 2023 |
| 1359 | Traver Oil & Gas Corporation | | Oil & Gas Operator | Sep 2000 |
| 1360 | Traver Oil Company | | Oil & Gas Operator | Sep 2000 |
| 1361 | Traver-Patterson Petroleum Inc | | Oil & Gas Operator | May 1990 |
| 1362 | Travers Resources, Inc. | Houston, TX 77056 | Oil & Gas Operator | Jun 2026 |
| 1363 | Traverse Oil Co | | Oil & Gas Operator | Nov 1983 |
| 1364 | Traverse Oil Co And Federal Oil Co | | Oil & Gas Operator | Nov 1983 |
| 1365 | Travis E. Duren | | Oil Operator | Jul 1995 |
| 1366 | Travis Oil Co | Los Angeles, CA 90024 | Oil Operator | Jan 1990 |
| 1367 | Travis Operating, LLC | Kingwood, TX 77345 | Oil & Gas Operator | Jun 2026 |
| 1368 | Travis Peak Resources LLC | Houston, TX 77002 | Oil & Gas Operator | Mar 2026 |
| 1369 | Travis, J. J., Trustee | Rockport, TX 78382 | Oil & Gas Operator | Dec 1996 |
| 1370 | Traxler, Joyce | Le Roy, NY 14482 | Gas Operator | Dec 2024 |
| 1371 | Traynor Oil & Gas Inc | Claremont, CA 91711-2837 | Oil & Gas Operator | Jan 2024 |
| 1372 | TRC Cypress Group LLC | | Oil & Gas Operator | Dec 2025 |
| 1373 | TRC Operating Company Inc. | | Oil & Gas Operator | Mar 2026 |
| 1374 | Tre'J Exploration, Inc. | | Gas Operator | Dec 1991 |
| 1375 | Treadaway Oil Co. | Balmorhea, TX 79718 | Oil & Gas Operator | Jun 2026 |
| 1376 | Treadstone Energy Partners, LLC | Houston, TX 77070 | Oil & Gas Operator | Jun 2016 |
| 1377 | Treadstone Energy PRTNR Op, LLC | Katy, TX 77494 | Oil & Gas Operator | Jun 2026 |
| 1378 | Treat Howard | Okmulgee, OK 74447 | Oil & Gas Operator | Oct 2014 |
| 1379 | Trebole Operating Company | | Oil Operator | Jul 1979 |
| 1380 | Treco Oil Company | Albany, TX 76430 | Oil & Gas Operator | Jun 2026 |
| 1381 | Tredegar Properties, Inc. | | Oil Operator | Jun 1990 |
| 1382 | Tree Operating, LLC | Graham, TX 76450 | Oil & Gas Operator | Jun 2026 |
| 1383 | Trees Oil Compan | | Oil Operator | Jan 1995 |
| 1384 | Trejim Operators, LLC | Pampa, TX 79065 | Oil & Gas Operator | Jun 2026 |
| 1385 | Trek Aec, LLC | Wichita, KS 67202 | Oil & Gas Operator | Feb 2026 |
| 1386 | Trek Exploration, Inc. | Pampa, TX 79065 | Oil & Gas Operator | Jun 2026 |
| 1387 | Trek Oil & Gas, Inc | Houston, TX 77002 | Oil Operator | Mar 1998 |
| 1388 | Trek Operating, LLC | Tulsa, OK 741520098 | Oil & Gas Operator | Mar 2021 |
| 1389 | Trek Petroleum Company, Inc. | Midland, TX 79707 | Oil & Gas Operator | Jun 2026 |
| 1390 | Trek Resources, Inc. | Dallas, TX 75207 | Oil & Gas Operator | Jun 2026 |
| 1391 | Tremo Corporation | Toronto, KS 66777 | Oil Operator | May 1998 |
| 1392 | Tren Energy LLC | El Paso, TX 79912 | Oil & Gas Operator | Jun 2026 |
| 1393 | Trenchco Inc | Shawnee, OK 74802-3577 | Oil & Gas Operator | Apr 2015 |
| 1394 | Trend Exploration Company | Midland, TX 79701 | Oil & Gas Operator | Mar 2008 |
| 1395 | Trend Exploration I LLC | Midland, TX 79701 | Oil & Gas Operator | May 2011 |
| 1396 | Trend Gas & Oil Inc | Jenks, OK 74037 | Oil & Gas Operator | Dec 2000 |
| 1397 | Trend Oil Co | Petaluma, CA 94954 | Oil & Gas Operator | Feb 2017 |
| 1398 | Trendsetter Production Co, Inc | | Oil & Gas Operator | Jul 2008 |
| 1399 | Trendwell Energy Corporation | | Oil & Gas Operator | Nov 2025 |
| 1400 | Trenmor Gas & Oil Co LLC | Frazeysburg, OH 43822 | Oil Operator | Dec 2023 |