Ouray
Ouray was settled in 1875, when gold and silver deposits were found near Mount Sneffels. Since 1877, mines in Ouray County have produced over $35,000,000 in gold and $32,000,000 in silver. The district is still quite active: in 1965, mines in this area produced more than $9,000,000 in gold, silver, copper, lead, and zinc, about a third of total Colorado production of these metals for that year.
A few miles south of Ouray, along Uncompahgre Gorge, an old mine clings to the slope below the Million Dollar Highway (U. S. 550). Abrams Mountain rises in the background. The Precambrian Uncompahgre Quartzite outcrops up to about the road level; Miocene Sunshine Peak [Rhyolite] caps the peak. (Jack Rathbone photo)
A mile north of Ouray a prominent intrusive [stock] marks the center of mining activity closest to Ouray. The richest deposits of the Ouray area, however, lie about five miles southwest, near Mount Sneffels and Red Mountain Creek. There, several large mines, including the famous Camp Bird mine, have operated for many years, extracting ore from hundreds of [veins] that underly the surface. Some of these veins are two to four miles long. They are in Tertiary volcanic rocks of the San Juan Formation. Quartz and calcite are the common [gangue] (non-economic) minerals, and [pyrite], [sphalerite], [galena], and [chalcopyrite] are the most abundant ores. Most of the silver is in the galena; gold occurs in streaks and nodules associated with quartz.
About ten miles south of Ouray, along the “Million Dollar Highway” (U. S. 550), the Red Mountain district lies on the northwest edge of the Silverton volcanic cauldron. It contains a number of small pipelike bodies very rich in silver-copper and silver-lead ores. Following the mid-Tertiary volcanism and ore intrusion, surface rocks in this area were intensely oxidized: resulting iron oxides now form the gaudy reds and yellows of Red Mountain and the slopes near Ironton. This alteration, as well as the fact that much of the area is covered with fallen rock, stream gravels, or glacial deposits, compounds difficulties of locating the small though high-grade ore deposits.
The Idarado Mine, on the east side of U. S. highway 550 near Red Mountain, used to produce ores from nearby volcanic pipes; now it produces from [veins] some distance to the northwest. The area is honeycombed with tunnels and shafts.