Those deposits are crushed and soaked in cyanide to separate the valuable ore from worthless rock. That rock waste is piled in dams, one after another. Snow melt perks through, making its way to the ocean, carrying the cyanide, acid drainage and heavy metals too small to be recovered.
I recommend you read up on the Pebble Mine project and the accidents that have occurred using this technology before you blast off...
Pebble mine is a different animal.. the ore is all surface..
cyanide is old technology... the ore can be concentrated but sent somewhere else to be processed.. at least five maybe six different metals present..
lots of current gold mines in Alaska.. little if any negative impact.. and lead mines as well...