A ring on the wall of the old Key Mill, at the Centennial mine. This was at the Centennial #3, which was a long abandoned copper mine (briefly) explored by Homestake in the 1980's. They even went so far as to build a mill (the "Key Mill") at the site, in some more or less featureless sheet metal buildings on the site. The mill was sold and torn down last year. However, not all of it is gone -- random cement pedestals and metal artifacts remain, standing in the late afternoon sun. Cliffs and Ruins blog • David Clark Photography store