Insider's reporter explored the abandoned Boston Mine in Colorado. It's now protected land but is said to have up to $50 million worth of gold hidden.

NPR's Mark Roberts reports on how one man's threat to destroy old silver mines on his property in Ouray County, Colorado prompted the National Trust for Historic Preservation to list the Red ...

The images of Colorado's Animas River over the past week have been jarring: ... Old coal mines still taint Ohio waterways. ... she said, “just like the pictures coming out from out West.