NEW AREAS FOR COAL MINING IN THE LOWER WHITE RIVER COAL FIELD, RIO BLANCO COUNTY, COLORADO

The Lower White River coal field, southeast of Rangely, Colorado, comprises an area of approximately 930 square miles (2,408 km2). Coals of the Upper Cretaceous Mesaverde Group crop out along the axis of the Douglas Creek Arch. Over 28 million short tons (25.4 m-mt) of low sulfur and low mercury content bituminous coal have been mined in the field since 1907. Lower White River contains an estimated resource of nearly 11.7 billion short tons (10.6 b-mt) of original coal from coal beds greater than 14 inches (0.36 m) in thickness at depths less than 6,000 feet (1,828 m).

The underground Deserado Mine is the only active mine, producing over 2 million short tons (1.8 m-mt) per year from the coal-bearing intervals of the Mesaverde Group. The B and D coal beds range in heat value from 10,800-11,230 Btu/lb (25,120-26,120 j/gm). Ash ranges from 4.4 to 8.5 percent and sulfur ranges from 0.4-0.5 percent. Mercury concentrations at Deserado are 0.04 mg/kg.

A recent study shows that the Lower White River coal field contains abundant coal in the southern part of the coal field, which could provide several billion short tons of underground mineable coal. Coalbed methane exploratory wells in T. 1 N., R. 100 W. indicate net coal from the combined B and D coal zone up to 32-ft (9.75 m) thick. These mineable coal beds were correlated south across the Lower White River coal field to Douglas Pass. Coal beds were correlated from 350 wells, and then mapped using Geographic Information Systems (GIS) to show structure and thickness. Land use and technological restrictions to coal mining were applied to the subsurface coal data through GIS to determine areas suitable to future mining. Land use restrictions at this time include over 1,900 petroleum wells in the field, and technological restrictions include over 50 sub parallel SW-NE trending normal faults with up to 300 ft (91.4 m) of throw.

These data indicate that the best new area for mining of the B coal (greater than 20 ft (6.1 m) thick) is in T. 2 S., R. 102 W., and the best new area for mining the D seam (greater than 10 ft (3.05 m) thick) is in T. 1 S., R. 101 W. Coal availability calculations for these areas indicate mineable coal regions on the order of 10 to 20 million short tons (9-18 m-mt) of reserve for both townships.