Exploration for copper in this area of the First Watchung Mountain may date back to at least the 1600ís. Crushed ore may have been used for tools and decoration by the Lenape tribe of Native Americans.
Another story holds that Hessian soldiers held captive near here by the Colonial Army during the Revolutionary War were compelled to dig for copper ore to support the war effort. The ore was of low quality and the exploratory mine never progressed more than 15 feet into the mountain.
Portions of the mine have collapsed and are visible to the north of the gorge. On the edge of the collapsed area, a large stone used for sluicing the ore can be seen.