LAST CHANCE RANGE (sulphur)
California's largest sulphur deposits are located on the western edge of Last Chance Range in Inyo County. First discovered in 1917, the sulphur lies in a mineralized area three miles long by one mile wide. A bedded deposit 16 to 30 feet thick contains ore values ranging from 30 to 80 percent sulphur. Estimated reserves in 1938 showed over a million tons of ore containing at least 40 percent sulphur. Most of the development of this area occurred in the late 1930s.
Six claims known as the Crater Group were developed in 1929-1930, with several shafts and a large open pit completed by the Pacific Sulphur Company of New York. This company produced approximately 12,000 tons of sulphur. In August of 1936 Sulphur Diggers Inc., obtained a lease on the Crater Group and operated them until September, 1937. Retorts were installed at the mine and 5,000 tons of 96 percent sulphur ore produced.
The Western Mining Company took over operations in 1938, built a new 100-ton retort and concentrated on mining, by open pit methods, an exposure of 10,000 tons of sulphur on the Crater Number Six Claim. A 125 horsepower boiler provided steam for the retorts, which consumed 3,250 gallons of water each day. 15 men were employed at the mine. An additional 15 worked at the refinery. In late 1941, an explosion destroyed the refinery. World War II finally caused operations to cease in August of 1942.
Adjoining the Crater Group on the south were the Fraction and Southwest Sulphur claims, comprising 18 acres, which developed a 6 to 12 foot sulphur vein. Further south, the Gulch Group were 10 claims located originally by James Jacoby in 1918. Half of the 20 foot wide sulphur vein on this property consisted of massive crystalline sulphur 90 percent pure. The richness and extent of sulphur reserves in this area is well proven. Their isolation and distance from an adequate water supply for milling operations have discouraged extensive development.