Prospectors looking for gold in 1860 were disappointed, but named the Mount Sopris that dominates the valley after their leader. After the American Civil War, the federal government concluded treaties with the Utes and otherwise began to encourage settlement in the region, that its rich mineral resources might be exploited. The surveys of Ferdinand Vandeveer Hayden in 1873 gave names to many other mountains and streams in the region and suggested the Crystal Valley might well be rich in coal.