April 1861, silver and some gold and copper lodes had been discovered by John Moss and others in what became known as El Dorado Canyon. In 1867, to secure the riverboat traffic and protect miners in the canyon from Paiute attacks the U.S. Army established Camp El Dorado, an outpost at the mouth of El Dorado Canyon that remained until it was abandoned in 1869. From 1870 the mines again were active to the point where from 1879 to 1907 El Dorado Canyon again had a post office, now in Clark County, Nevada. The mines continued to produce ore until World War. Wikipedia
So, the gentleman that owns the mine leads people on tours. When coming to one intersection of shafts you can just make out a skeleton in tattered clothes leaning against the rock wall. When I asked who that was he said "the first boy that dated my daughter" then he turned and kept walking.