| 1 | D & B Gas Prod LLC | Kittanning, PA 16201-7123 | Oil & Gas Operator | Dec 2024 |
| 2 | D & L Energy Inc | Canton, OH 44718 | Oil & Gas Operator | Dec 2016 |
| 3 | D & S Energy Corp | Tiona, PA 16352-0102 | Oil & Gas Operator | Dec 2018 |
| 4 | Dakota Oil & Gas Co | Delmont, PA 15626-2408 | Oil & Gas Operator | Dec 2024 |
| 5 | Dakota Opr Co Inc | Indiana, PA 15701-0444 | Oil & Gas Operator | Dec 1999 |
| 6 | Dale U & Martha E Livermore | Brookville, PA 15825-7524 | Gas Operator | Dec 2023 |
| 7 | Dannic Energy Corp | Indiana, PA 15701-1532 | Oil & Gas Operator | Dec 2024 |
| 8 | Dawn Energy SVC | Templeton, PA 16259-3616 | Gas Operator | Dec 2024 |
| 9 | De LTD Family Partnership | Punxsutawney, PA 15767-2646 | Oil & Gas Operator | Dec 2022 |
| 10 | Deitz Edith | Clarion, PA 16214-9416 | Oil & Gas Operator | Dec 2009 |
| 11 | Deitz Gas & Oil Inc | Clarion, PA 16214-3215 | Oil & Gas Operator | Dec 2024 |
| 12 | Destiny Inc | Sprankle Mills, PA 15776-9705 | Gas Operator | Dec 2009 |
| 13 | Devonian Resources Inc | Pikeville, KY 41502 | Oil & Gas Operator | Dec 2024 |
| 14 | Diversified Oil & Gas LLC | Jackson Center, PA 16133 | Oil & Gas Operator | Jan 2025 |
| 15 | Diversified Production LLC | Keithville, LA 71047 | Oil & Gas Operator | Mar 2025 |
| 16 | DK Gas Inc | Hawthorn, PA 16230-0228 | Oil & Gas Operator | Dec 2006 |
| 17 | DL Resources Inc | Ludlow, PA 16333-0039 | Oil & Gas Operator | Dec 2024 |
| 18 | Dorward Energy Corporation | Saint Petersburg, FL 33701-3255 | Oil & Gas Operator | Dec 2024 |
| 19 | Double Aa S LLC | Mayport, PA 16240-5638 | Oil & Gas Operator | Dec 2019 |