Hickory Run State Park is a 15,990-acre park in Pennsylvania’s Pocono Mountains, known above all for the Hickory Run boulder field, the largest of its kind in the Appalachian region. Spanning about 16.5 acres, this broad expanse of sandstone and conglomeratic sandstone boulders preserves evidence of ancient periglacial freezing and thawing, with some rocks thought to have remained near the surface for about 600,000 years through multiple glacial and interglacial cycles. The park also offers seasonal recreation, including swimming and skating at Sand Spring Lake, hunting, forty-four miles of trails, a rhododendron-lined stream path, a waterfall walk, and winter cross-country skiing.