Boulder Batholith - Potential Montana Uranium Province

THE Boulder batholith of western Montana may be considered a uranium province: a regional geologic environment within which uranium is found in uncommon amounts. Reconnaissance examinations indicated that the Atomic Energy Commission should undertake an evaluation of the potential of this area for uranium production. The AEC has been assisted by the U. S. Geological Survey which has given priority to selected uranium-bearing areas in overall studies of the mineral deposits of the batholith and adjacent regions. Although no out- standing uranium deposits have been discovered, uranium ore has been produced from three widely separated deposits upon which most of the exploration to date has been directed. The intrusive mass referred to as the Boulder batholith occupies a strip of mountainous country about 18 miles wide between Butte and Helena, Mont., covering an area of approximately 1000 sq miles. Elevations range from 3500 ft along Prickly Pear Creek to nearly 9000 ft near Elkhorn Peak a few miles to the east. Except for a few flat-lying valley lands, the region is wooded with lodgepole pine and fir. Though mainly dependent upon mining ventures in the past, the area now is supported, outside of the Butte district, almost wholly by agriculture and some lumbering.