Sinkhole Trail

Sinkhole Trail explores the karst geology of Monte Sano Mountain, visiting a series of limestone sinkholes that represent the surface expression of an extensive cave and groundwater system beneath the mountain. Monte Sano sits atop a thick sequence of Ordovician-age limestone, and rainwater that infiltrates the mountain's surface dissolves the limestone over time, creating underground voids that eventually collapse to form surface sinkholes. The sinkholes along this trail range from small bowl depressions a few feet across to dramatic collapse features 30 feet deep and 50 feet in diameter. The vegetation inside the sinkholes differs markedly from the surrounding upland forest due to cold air pooling in the depressions, creating frost pockets where northern plant species grow alongside warm-adapted piedmont flora. Interpretive panels along the trail explain the karst processes responsible for the sinkholes and describe the cave systems that extend beneath the mountain. Cave salamanders, a species restricted to karst cave systems, inhabit the dark, cool interiors of the deeper sinkholes. No entrance fee is charged. This trail provides a unique educational experience in geology and ecology not duplicated by any other trail in the Monte Sano park system. The route is well-marked with clear signage at junctions with the park's other trails.