| Rank | State | Undg. Reserve | Surface Reserve | Total Reserve |
% of Total U.S. |
| 1 | Montana | 71.0 | 49.2 | 120.1 | 25.4 |
| 2 | Illinois | 63.1 | 15.5 | 78.5 | 16.5 |
| 3 | Wyoming | 42.6 | 26.1 | 68.7 | 14.4 |
| 4 | West Virginia | 33.0 | 5.0 | 37.9 | 8.0 |
| 5 | Kentucky | 24.5 | 5.7 | 30.2 | 6.3 |
| 6 | Pennsylvania | 28.1 | 1.4 | 29.5 | 6.1 |
| 7 | Ohio | 12.9 | 5.8 | 18.6 | 4.0 |
| 8 | Colorado | 12.2 | 4.9 | 17.1 | 3.6 |
| 9 | Texas | 0.0 | 13.5 | 13.5 | 2.7 |
| 10 | Indiana | 8.9 | 1.4 | 10.3 | 2.1 |
| All Other States | 24.6 | 25.1 | 50.1 | 10.9 | |
| Total U.S. | 320.9 | 153.6 | 474.5 | 100.0 |