tomorrow. The Smelter Stacks are located at BHP's San Manuel Operation which is located 45 miles outside of Tucson. I imagine these are the 500 footers. You can see them from just about everywhere around there.
I worked on a small project there in the '90's. It was an amazing place. It was the largest underground copper mine in the US and accounted for 25% of the US copper output.
Brandenburg is doing the mine closure and demolition. You would think in these days of high copper prices that these copper mining and smelting operations could be made viable. I have never seen so many of them coming out for bid for demolition in such a short period before.