From scope of report: "The fluorite district in the western part of the Thomas Range, Juab County, Utah, is one f the newest mining districts in western United States; since 1950 it has been the largest producer of fluorite west of the Mississippi River. The present report covers the geology of the entire fluorite producing area, and supplements an earlier report...on the individual mining properties."
From abstract: The Thomas Range fluorite district, on Spor's Mountain in the western part of the Thomas Range, Juab County, Utah, is approximately 6 miles long and 2 miles wide, and contains almost no unclaimed land. The fluorite production of the district, since its discovery in 1943, has been 35,700 short tons. It was obtained from 12 different ore bodies on eight different properties. G. P. Spor, Ray Spor, and Chad Spor; Albert Willden and Earl Willden; T. A. Claridge; and W. E. Black and F. B. Chesley were the only groups producing fluorite in the district in August 1950.