The trail's southern terminus begins in Gambrill State Park (GMP). The trail continues north through GMP for approximately and then leaves the park and enters the Frederick Municipal Forest (Frederick City Watershed). The trail travels north for through the Forest, staying mostly to the east of the ridge crest on the bench of the mountain. As the trail enters Cunningham Falls State Park (CFSP) it descends northeasterly off the bench and into Catoctin Hollow reaching its lowest elevation of as it crosses Catoctin Hollow Road. After crossing the road the trail turns northwesterly and then climbs to its highest elevation of , atop Bob's Hill. After traveling through CFSP the trail enters Catoctin Mountain Park (CMP), a unit of the federal National Park Service. The trail traverses through the Park to its northern terminus at Mt. Zion Road, north of Owens Creek Campground in CMP. From there, the Appalachian Trail may be reached by traveling west on Mt. Zion Road to Raven Rock Road for .