 The worst rocks are in the northern half of the state, north of the Susquehanna River.Many consider Pennsylvania one of the easier parts of the AT, since it is mostly walking on ridges with relatively small elevation changes compared to many other states.In 1984, the ad-hoc citizen's group Citizens Against the New Trail (CANT) and four local townships organized to oppose suggested changes by the National Park Service (NPS) to the route in the Great Cumberland Valley between Carlisle and Harrisburg, the longest route that follows a paved highway.