There is so much to see on this 3.5 mile loop.  Give yourself a heap of extra time on this one to allow for exploring.  The trailhead begins across the street from the parking area descending past abandoned zinc mines to a beautifully formed creek.  Notice the smooth channels that centuries of water have turned the rock into.  The trail takes you to the Indian Rock House, where bluff dweling indians once took shelter.  Don't just step into the cave and leave or you will miss the multiple caves and underground stream that surfaces towards the back of the cave.  When you're ready to leave, follow the trail past the natural bathtub, up into the CCC rock quarry and back to the highway.  The trail does not end exactly where it begins.  Hang a left on the highway to find your vehicle.