A rock chute at the Centennial #3 copper mine in Michigan's Copper Country. Skips (rock cars mounted on rails, which ran up and down the shaft) delivered rocks into the rockhouse, where they were crushed, sorted, and processed. Copper-bearing rock came down this chute into waiting ore cars (or sometimes trucks) to be delivered to a mill. The rusted wall in the background is part of another large bin designed to store rocks.
The ruins here are left over from Homestake's exploration and re-opening of the mine in the 1970s. The mine originally opened in 1876, quickly closed, reopened under Calumet and Hecla, closed again, and reopened once more for Homestake -- which also quickly closed the mine.
Edit: As of 2013, everything you see here has been torn down. Alas.