US-15 continues south from Gettysburg across the Maryland border, and there’s little to stop for until Thurmont (pop. 6,125), “Gateway to the Mountains.” The green expanse of Catoctin Mountain Park, fully recovered after previous centuries of logging activity, protects some 5,810 acres of hardwood forest, a handful of 1,500-foot peaks, and the presidential retreat at Camp David, hidden away in the woods and strictly off-limits to visitors (for security reasons, Camp David doesn’t even appear on park maps). The Catoctin park visitors center (301/663-9388, daily) along Hwy-77 two miles west of US-15 provides information on cabins, camping, and maps of the many hiking trails, including a short trail from the visitors center to the preserved remains of the Blue Blazes whiskey still, where rangers demonstrate moonshine-making on summer weekends.
Spreading along the south side of Hwy-77, Maryland-run Cunningham Falls State Park offers more natural scenery and a very pleasant swimming area in Hunting Creek Lake. There’s a snack bar and boats for rent, and a half-mile trail leads to the eponymous cascade.