I love exploring and it was a phenomenally beautiful evening in Superior in mid-December. Imagine all this metal (1000-foot lakers, conveyer bridges, docks, tracks) was flipped upward - the red contents of the pits now sit on the surface of the earth formed into structures and transportation that allow the creation of more pits.
In 1910, the world production of pig iron was 66.5 million tons. In 2012 1.1 billion. (Source: minerals.usgs.gov) It requires 2 tons of ore to make a ton of steel. And a half ton of limestone. More info here.
For more about the Allouez docks, check out Substreet.