Situated in the middle of Seneca State Park and the middle of the Greenway Trail, Black Rock Mill is a good place to start exploring. Unlike the northern end of the park and the trail, there are hardly any developed amenities for many miles in either direction of Black Rock Mill. Lake Clopper is over 5 miles north. The Visitor Center there is 6.2 miles distant. The C&O Canal, in the other direction, is 7.2 miles south. Other than bridges, and a few road crossings, there’s not much else made by man in-between. Running or hiking the trail definitely gives you a feeling of being out in the country.