The old timers typically washed these areas down to bedrock, and some areas appear terraced. I would imagine this is because these hydraulic mines were generally where the miners found old Tertiary river channels on the sides of mountains that were gold-bearing.

The type of mine dump that is best for metal detecting are the ones that consist of mixed sizes of rock and are located near some sort of excavation, commonly a shaft or adit. Sometimes the piles located along a trench dug by the miners can be productive as well.

There are currently three controlling agencies or entities over suction dredging in California—and you can make that four if the state legislature decides to further muddy the waters with additional legislation to block suction gold dredging in the state.

Once I started dredging with heated water pumped into my wetsuit, I never went back to not having heat except late in the summer when the water is very warm.