Primitive, summer only, free, 46 sites; 15.1 miles, moderate to difficult; High Falls is the most remote of the waterfalls in St. Lawrence County and is located in the southern most portion of the County. While the hike into the falls is well worth it, do not be surprised when you see one of the smallest falls of the county. While High Falls is only 15 feet high, its name is derived from the fact that it is the largest drop on that branch of the Oswegatchie River, a calm, slow-moving river