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.

Picking the right spot to placer has to do with years of experience, and a little luck. The textbooks can tell you where it should be, but sometimes the rules just don’t seem to apply.

Within this area, about two million ounces of gold and fifty million ounces of silver have been mined. Faults, dikes, veins and fissures that carry the ore form a concentric radial pattern—like spokes on a wagon wheel—around the caldera core.

When I teach people about finding gold, I often explain that it is helpful to think of any river or stream that carries gold as being something like a sluice box.