That was taken at the nearby Pahaquarra Coppermines.
They're in New Jersey, and are not being worked.
That was on the rock face in the 'open pit' quarry on the hilltop.
There's adits (horizontal shafts) and a few boreholes about, but the place of most interest is the quarry.
Have some rather plain pics of the rocks themselves, but since there's nothing to judge from, it appears to be plain old rocks.
I didn't know there were ever copper mines in NJ. They are up and down AZ, but there may only be a couple still active. The deepest I've gone into the earth was to an old borate mine just outside of Death Valley.