Coming into Silverton we could see the denuded spots on the hills off in the distance where hard rock mining had taken place in the late 1800s and early 1900s. Our train ranger commented that there had once been 2500 mines in the region. It is the most mineralized country in our continent. Mining in the San Juans was initially for gold, followed by silver. Following those ores were the less common as lead, copper and zinc. After WW11 the area experienced a decline in mining. The last mine closed in 1991. Source for some of this information was taken from America's Railroad by Robert Roytem.