Further to my last post, here is some info on the Super Pit gold mine. Notice they are down 360m after approx 10 years of work, this is why I think Khersons royalty suggestion, may hold some substance. But then, you never know, the Tesoro could be bought outright, we saw evidence of that in past buyouts, where resources were bid on in the billions and 1 over 100 billion.

http://en.wikipedia.org/wiki/Super_Pit_gold_mine