Coppertown Mining Museum Wikimedia Commons has media related to Cliffs Shaft Mine.James D. Schuster - Marquette Range Iron Mining Heritage Theme Park Inc. Underground, the Cliffs Shaft Mine was one of the largest iron mines in Michigan, containing sixty five miles (a hundred and five km) of tunnels operating http://2-018405.amoblog.com/how-much-power-does-it-take-to-create-a-bitcoin-25548802