Solar energy can be used for any size placer or hard rock mining operation. It is most practical for small and longer-term operations provided your mine is not located in a dense forest.

• EPA declines to impose additional regulations and financial requirements on hardrock miners
• “Baffling” ruling in suction gold dredging court case

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.