| Coal Resources, Reserves, and Mine Sizes, Montana | |||
|---|---|---|---|
| Category | Type of Mining | Total | |
| Underground | Surface | ||
| Demonstrated Reserve Base | |||
| (Million Short Tons as of January 1, 2000) | 70,958 | 48,562 | 119,520 |
| Estimated Recoverable Reserves | |||
| (Million Short Tons as of January 1, 1997) | |||
| Sulfur Content (pounds per million Btu) | |||
| <0.61 (low sulfur) | 25,396 | 24,949 | 50,345 |
| 0.61-1.67 (medium sulfur) | 9,648 | 11,924 | 21,573 |
| >1.67 (high sulfur) | 878 | 2,514 | 3,392 |
| Total | 35,923 | 39,387 | 75,310 |
