| 1401 | Wood River Oil & Refining Co | | Oil & Gas Operator | Dec 1998 |
| 1402 | Woods Petroleum Corporation | Oklahoma City, OK 73112 | Oil & Gas Operator | Mar 2015 |
| 1403 | WPX Energy RM Company | Tulsa, OK 74101 | Oil & Gas Operator | Jun 2014 |
| 1404 | WPX Energy Rocky Mountain LLC | Tulsa, OK 74101 | Oil & Gas Operator | Jul 2025 |
| 1405 | WRC Energy LLC | Tulsa, OK 74135 | Oil & Gas Operator | Jul 2025 |
| 1406 | Wulf Oil Co | | Oil & Gas Operator | Dec 1984 |
| 1407 | Wyatt Petroleum Corporation | Evergreen, CO 80437 | Gas Operator | Jul 2002 |
| 1408 | Wychgram Daniel C | Thermopolis, WY 82443 | Oil Operator | Feb 2001 |
| 1409 | Wynn-Crosby Operating, LTD. | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |
| 1410 | Wyoil Corp | Buffalo, WY 82834 | Oil Operator | Aug 2025 |
| 1411 | Wyoming Energy Partners LLC | | Oil Operator | Aug 2025 |
| 1412 | Wyoming Mineral Exploration LLC | Casper, WY 82602 | Oil Operator | Dec 2006 |
| 1413 | Wyoming Oil & Minerals Inc | Casper, WY 82601 | Oil & Gas Operator | Jun 2001 |
| 1414 | Wyoming Resources Corporation | Rapid City, SD 57702 | Oil & Gas Operator | Oct 2018 |
| 1415 | Wyoming Western Oil | Pine Bluffs, WY 82082 | Oil Operator | Sep 2019 |
| 1416 | Xeric Oil & Gas Corporation | Midland, TX 79702 | Oil & Gas Operator | Apr 2014 |
| 1417 | Xog Operating LLC | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 1418 | Xoil Inc | Aurora, CO 80016 | Oil & Gas Operator | Jul 2023 |
| 1419 | XPR Wyoming LLC | | Oil & Gas Operator | Aug 2025 |
| 1420 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Oct 2025 |
| 1421 | Yates Drilling Company | Artesia, NM 88210 | Oil & Gas Operator | Dec 2021 |
| 1422 | Yegen E C | Casper, WY 82604 | Oil & Gas Operator | Mar 2015 |
| 1423 | Young Marshall R Oil Co | Fort Worth, TX 76107 | Oil & Gas Operator | Mar 2011 |
| 1424 | Z & S Construction Co Inc | Kimball, NE 69145 | Oil & Gas Operator | Jun 2025 |
| 1425 | Zavanna Resources LLC | Denver, CO 80202 | Oil & Gas Operator | Jun 2025 |
| 1426 | Zenergy Inc | Tulsa, OK 74136 | Oil & Gas Operator | Jul 2025 |
| 1427 | Zerbst James E | | Oil & Gas Operator | Apr 2007 |