South Horn is the southerly summit of The Horns, a pair of conical subpeaks at the western end of the Bigelow Range in Franklin County, Maine. At 3,805 feet, it sits just below the range's 4,000-foot main summits but qualifies for the New England Hundred Highest. The mountain takes its name from Major Timothy Bigelow, who scaled the ridge in October 1775 while scouting routes for Benedict Arnold's ill-fated expedition toward Quebec, with Arnold's force passing along the Dead River to the north. Much of the range lies within the 10,540-acre Bigelow Preserve, a National Natural Landmark set aside in 1976 in response to a proposed ski resort.
The summit is a small open clearing with wide views south, east, and west. Horns Pond, a glacier-carved tarn, lies directly below to the southwest, and the higher hulks of Avery and West Peaks stretch away to the east along the ridgeline. North Horn (3,792 ft) sits just 0.2 miles away as an easy side-trip.
Most hikers approach South Horn as part of a challenging loop via the Fire Warden's and Horns Pond Trails, a 12-plus-mile circuit from Stratton Brook Pond that can also take in Avery and West Peaks. The Horns Pond lean-to, maintained by the Maine Appalachian Trail Club, sits 0.8 miles below the summit and makes overnight trips practical. Snow lingers well into May, and winter visits call for microspikes or crampons above the pond.
