I am very familiar with this operation:
Wiki:
Goldstrike is a gold mine in Eureka County in north-eastern Nevada. It is located on the Carlin Trend, a prolific gold mining district. It is owned and operated by the world’s largest gold mining company, Barrick Gold. Goldstrike is the largest gold mine in North America. Since Barrick acquired Goldstrike in 1986 it has produced 42 million ounces of gold.[
Like most Carlin type gold deposits in Nevada the gold was epithermally deposited in carbonate or silicate sedimentary rocks. The source of the heat was magmatic but the exact mechanism is still under debate. The Betze-Post deposits are up to 6,000 feet (1,800 m) long, 600 feet (180 m) thick and 800 feet (240 m) wide. In 2007 the average processed gold grade was 0.136 troy ounces (4.2 g) per ton of ore, with a recovery rate of 85.5%.[2
Folks around here in Nevada would be all over 1 oz per ton.
http://www.geo.msu.edu/extra/geogmich/gold.html
It depends how easy the material is to get at. Lots of these mines failed because of poor methods of extraction and production. You can bet your bottom dollar that they would NEVER let them use sulfide mining methods unless they let them transport that ore to a facility where they have the permitted leech fields working.
This dam is located right smack in the heart of the gold areas of CA. And if any geologists look at that colour, they will come to the same conclusion that it looks good. They need to sample it and see. But the dumbasses from that state would simply pass on it and never give it a chance. Its easier to beg for somebody elses money to fix that spillway-the federal government...you and I.