Marysvale, Utah, is an area of special geological interest. The district is a source of consistent uranium production where ores occur in veins related to igneous activity. Here is an unusual illustration of the nature of hydrothermal alteration in connection with vein formation. The region furnishes data on the relationship between centers of igneous invasion and the sedimentary accumulations of the Colorado Plateau.

The area of uranium production lies in the vicinity of the Prospector, Freedom No. 2, Bullion Monarch, and near-by workings and constitutes a zone about a mile long by half a mile wide. Numerous prospects lie in...