Alaska: A river runs through it, and that's the problem

If built, the Kerr-Sulphurets-Mitchell mine near the British Columbian border could produce more than 10 billion pounds of copper, 133 million ounces of silver, 38 million ounces of gold and 200 million pounds of molybdenum. It would also produce more than 2 billion tons of tailings, and one of its three open pit mines would be about as deep as the deepest open pit mine in the world today.
http://juneauempire.com/outdoors/2014-04-03/river-runs-through-it-and-thats-problem#.Uz6fbs5zvEw