Just to add:

BHP's Base Metal North America is in Tucson, AZ

http://www.bhpbilliton.com/home/businesses/Pages/GlobalOperationsMap.aspx

Escondida is owned by BHP...

It is currently the highest producing copper mine in the world. Its 2007 production of 1.483 million tons of metal was worth US$ 10.12 billion. The mine is owned 57.5% by BHP Billiton, 30% by Rio Tinto, 10% by JECO, a Japanese consortium headed by Mitsubishi and 2.5% by JECO 2, a consortium with the same owners but different shares.

Now is it possible that BHP was looking at Schaft Creek...(they love long mine life). Said here we'll take this of your hands, but we like how you operate you should look at this property next to us in Arizona...(Van Dyle Sombrero)