The Summitville mine was the scene of a major environmental disaster in the 1990s when the hastily installed liner of a cyanide-laced tailing pond began leaking heavily. Summitville is in the Summitville caldera one of many extinct volcanoes making up the San Juan Volcanic Field. One, the La Garita Caldera, is 35 miles in diameter. Large beds of lava, some extending under the floor of the San Luis Valley are characteristic of the eastern slope of the San Juans.
There is some tourism in the region, with the narrow gauge railway between Durango and Silverton being an attraction in the summer. Jeeping is popular on the old trails which linked the historic mining camps, particularly thrilling is the Black Bear Road. Visiting old ghost towns is popular as is wilderness treking and mountain climbing. The San Juans are extremely steep, only Telluride has made the transition to ski resort. Purgatory is a small ski area north of Durango near the Tamarron Resort. There is also sking on Wolf Creek Pass, an area used mostly by locals.