By A. H. KOSCHMANN and M. H. BERGENDAHL - USGS 1968
Ouray County is in southwestern Colorado in an area drained by the headwaters of the Uncompahgre River, a tributary of the Gunnison River. The mineralized areas are in the southern part of the county within the San Juan Mountains and include the Sneffels-Red Mountain and the Uncompahgre mining districts.
Ouray County was originally part of territory that was owned by the Ute Indian Tribe and that was ceded to the United States in 1873. Until 1873 the area had been little explored, but after the treaty was ratified, settlers and prospectors overÂ¬ran the county (Henderson, 1926, p. 24). By 1874 nearly four-fifths of the claims were on silver lodes; however, rich deposits of gold as well as silver were found in 1875 in the Mount Sneffels area, and the famous Camp Bird mine, the largest gold producer in the region, was located in 1877 (W. S. Burbank, in Vanderwilt and others, 1947, p. 403). The area developed rapidly, and additional discoveries were made in the Red Mountain area. By 1896, however, increased mining costs, a drop in the price of silver, and depletion of the rich surface ores caused many of the mines to close, although the Camp Bird conÂ¬tinued to be a significant producer until 1917. The mine was reopened in 1926 and was operated sporadically through 1956. Total gold production of Ouray County through 1959 was about 1,911,000 ounces, more than half of which came from the Camp Bird mine.
SNEFFELS-RED MOUNTAIN DISTRICT
The Sneffels-Red Mountain district is in southern and southwestern Ouray County, 8 to 12 miles from Ouray. The Sneffels camp is at the head of Canyon Creek in Imogene Basin west of Hayden Mountain, and the Red Mountain camp is at the head of Red Mountain Creek east of Hayden Mountain.
The district is the principal gold producer in Ouray County and one of the leading producers in the San Juan region, but little is known about its production in the early years. According to W. S. Burbank (in Vanderwilt and others, 1947, table 8, p. 404-405), deposits of late Tertiary age in Ouray County to 1945 produced about 1,693,000 ounces of gold, most of which came from the Sneffels area. The Camp Bird mine, the principal producer of metals in Ouray County until it closed at the end of 1956, produced, from 1896 to 1916, gold, silver, lead, and copper valued at $27,269,768, of which at least $21,884,894 (1,058,774 ounces) was in gold (Henderson, 1926, p. 185). Production of other mines in the district has been small and sporadic. Total gold output of the district through 1959 was indicated to be about 1,723,000 ounces.
The Sneffels-Red Mountain district and the adjoining Telluride district to the southwest, in San Miguel County, are geologically contiguous, and therefore they are treated as a geologic entity in the following description.
The main geologic feature of the area is the Silver volcanic basin which Burbank (1941, p. 151) divided into two distinct parts or provinces: (1) an interior downfaulted circular block, the caldera, which may be subdivided into a hub of tilted and locally faulted rocks, surrounded by a ring of highly faulted rocks, and (2) an exterior unit of relatively undisturbed but fissured rocks. The Sneffels and Telluride districts are in the exterior unit, on the northwest flank of the caldera; the Red Mountain area is in the northern part of the highly faulted outer ring.
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