Yeah, all these tailing made me curios too, just wanted to see if where i live was dredged or not, there are tailings all around here Folsom to Rancho. Anyways i dug a hole in my back yard recently( had to remove tree stomp anyway), but 7 feet of overburden dirt( made me happy as i realized that dredges didn't go that extra 1/4 mile in my direction ), after 7' feet of digging i hit gravel and river rock, im about a foot and half or two deep in to gravel, ran 12 buckets last Sunday, only got 10-12 micro speks, waved my detector over every quartz rock i pulled out . Thinking about giving up on this idea, very dificult to get dirt out of the hole and dont want to ruin my back yard with piles of dirt and rock,plus dont want to freak my neighbors out , as i live in saburbs .
Sorry for typos, using my phone.