Steve,
That is an old abandoned Gold Mine and I think that mountain has every element know to man kind in it. They call it the Iron Mountain Mine. There is iron, gold, silver, copper, and things that I don't even know what they are. When it rains the water comes doen through the fissures of the rock and into the mine and leaches out all that toxic stuff. They have spent millions and still don't have a solution. They did build a debree dam several years ago with the idea it would catch the water and the toxic waste would sink and the water would go over the overflow. First problem was they forgot that after so long that crap would fill up the holding lake and it started going over the overflow. They put some kind of steel in there to stop that and the steel was supposed to last for at least 75 years. They had to replace it in 3 years. They are still doing studies to try and figure out how to stop that. You should see the small river that is below that place where it has drained into it.
Ron