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 father-son duo spent years combing this bit of Pennsylvania wilderness with high-end metal detectors, drills and other tools to prospect for a fabled cache of Civil War gold.

The pit was a classic one—exposed shale bedrock with all the material being washed out one end of the pit. Within a few minutes I had a nice mellow signal that was in open ground.