All Copper Country mines of any size at all had a dry house: a place where miners could change out of their everyday clothes, and into their mining gear (and back again). Sometimes they could even wash and warm up a bit, have a smoke, and shoot the breeze.
Most drys were fairly small. This, however, is the extremely large dry house from the Quincy Mine -- two stories tall and very long. Inside, you can still find some of the old lockers used by the miners.