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.

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.