In addition to picnic pavilions and athletic fields, Upper Milford's largest park contains a chunk of woods. In that woods are shallow depressions that some people might dismiss as the kinds of holes created when high winds uproot large trees. In fact, the indentions are the only remaining evidence that Native Americans quarried jasper from pits throughout this area for thousands of years before European settlers drove them out.

The smooth but sharp stone, which comes in autumn hues of red, brown and yellow, was worked into arrowheads, knives and other tools. Objects fashioned from this jasper have have found in archeological sites in several neighboring states.