| 801 | Willard M Cline | Bradford, PA 16701-1715 | Oil & Gas Operator | Dec 2022 |
| 802 | William L Horner Energy | Oliveburg, PA 15764-8411 | Gas Operator | Dec 2014 |
| 803 | William M Mauersberg | Sigel, PA 15860-2402 | Oil & Gas Operator | Dec 2009 |
| 804 | William McIntire Coal Oil & Gas | Shelocta, PA 15774-0171 | Oil & Gas Operator | May 2022 |
| 805 | William Southwell & Son Oil LLC | Warren, PA 16365 | Oil & Gas Operator | Dec 2024 |
| 806 | Wilmoth Clark Exploration & Prod LLC | Glen Campbell, PA 15742-0159 | Gas Operator | Dec 2008 |
| 807 | Wilmoth Interests, Inc. | Marion Center, PA 15759 | Oil & Gas Operator | Mar 2025 |
| 808 | Wind River Exploration Inc | Sewickley, PA 15143 | Oil & Gas Operator | Jun 2025 |
| 809 | Windfall Oil & Gas Inc | Falls Creek, PA 15840-2617 | Gas Operator | Dec 2024 |
| 810 | Winfall Energy Inc N V | Vandergrift, PA 15690-2001 | Oil & Gas Operator | Dec 2024 |
| 811 | Wood Drilling LLC | Kittanning, PA 16201 | Gas Operator | Dec 2024 |
| 812 | Wood William C | Kittanning, PA 16201-4328 | Oil & Gas Operator | Dec 2018 |
| 813 | XPR Resources LLC | Canonsburg, PA 15317-5862 | Gas Operator | Jul 2025 |
| 814 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Oct 2025 |
| 815 | Yeagle George W | Warren, PA 16365-0924 | Oil Operator | Dec 2010 |
| 816 | Zama Petro Inc | Clinton, WA 98236-0100 | Oil & Gas Operator | Dec 2024 |
| 817 | Zenith Exploration Co Inc | Washington, PA 15301 | Oil & Gas Operator | Dec 2014 |
| 818 | Zilhaver Brian K | Cambridge Springs, PA 16403-4114 | Gas Operator | Dec 2024 |
| 819 | Zoran Oil & Gas Co | Jefferson, OH 44047 | Oil & Gas Operator | Dec 2024 |