South Mountain (Maryland and Pennsylvania)

South Mountain is the northern extension of the Blue Ridge Mountain range in Maryland and Pennsylvania. From the Potomac River near Knoxville, Maryland in the south to Dillsburg, Pennsylvania in York County, Pennsylvania in the north, the 70 mi range separates the Hagerstown and Cumberland valleys from the Piedmont regions of the two states.

The Appalachian Trail follows the crest of the mountain through Maryland and a portion of Pennsylvania.

Geography
South Mountain begins at the Potomac River as a low, narrow ridge, barely one mile wide and only 1200 ft above sea level at its crest. South of the Potomac River in Virginia, the ridge continues as Short Hill Mountain for about 12 mi before subsiding near the town of Hillsboro. South Mountain in Maryland gradually grows higher and wider towards the north. Near the Pennsylvania border, the mountain merges with the hills of the parallel Catoctin Mountain range to the east and becomes more like a low mountain range than a single crest. North of U.S. Route 30 in Pennsylvania, the South Mountain highlands reach their greatest width, over 12 mi, and several summits top 2000 ft. The mountain then turns more to the east and becomes a series of small rocky hills between Mount Holly Springs and the northeastern end of the mountain at Dillsburg, Pennsylvania.

Maryland
From south to north:
 * Lambs Knoll, 1758 ft above sea level
 * Monument Knob, 1540 ft
 * Bartman Hill, 1400 ft
 * Pine Knob, 1714 ft
 * Buzzard Knob, 1520 ft
 * Quirauk Mountain, 2150 ft, highest point on South Mountain in Maryland

Pennsylvania
From south to north, then east:
 * Mount Dunlop, 1720 ft
 * Monterey Peak, 1663 ft
 * Clermont Crag, 1627 ft
 * Wildcat Rocks, 1772 ft
 * Virginia Rock, 1818 ft
 * Buzzard Peak/Chimney Rocks, 1946 ft
 * Snowy Mountain, 2090 ft
 * Green Ridge, 1980 ft
 * Mount Newman, 1784 ft
 * Piney Mountain, 1904 ft
 * Big Pine Flat Ridge, 2100 ft, highest point on South Mountain in Pennsylvania
 * Big Flat Ridge, 2065 ft
 * East Big Flat Ridge, 2070 ft
 * Mount Holly, 1504 ft
 * Long Mountain, 1583 ft
 * Center Point Knob, 1075 ft, midpoint of the Appalachian Trail in 1935
 * White Rocks, 1105 ft

Maryland
From south to north:
 * Crampton's Gap, 930 ft, between Burkittsville and Gapland
 * Fox's Gap, 1070 ft, between Middletown and Boonsboro
 * Harman Gap (Oeiler's Gap), 1570 ft, east of Cavetown
 * Turner's Gap, 1071 ft, between Middletown and Boonsboro, traversed by U.S. Route 40 Alternate

Pennsylvania
From south to north:
 * Monterey Gap, 1330 ft, at Blue Ridge Summit (see also Fairfield Gap)
 * Pass near Mount Newman, 1380 ft, traversed by U.S. Route 30

Maryland
From south to north:
 * South Mountain State Park, length of the ridge crest in Maryland
 * Gathland State Park, Crampton Gap
 * Washington Monument State Park, near Boonsboro
 * Greenbrier State Park, near Boonsboro

Pennsylvania
From south to north:
 * Michaux State Forest, covering most of the mountain
 * Caledonia State Park, east of Fayetteville
 * Kings Gap State Park
 * Pine Grove Furnace State Park, current midpoint of the Appalachian Trail

Conservation
In Pennsylvania, the region surrounding is the focus of a Conservation Landscape Initiative, led by the Pennsylvania Department of Conservation and Natural Resources (DCNR) and the Appalachian Trail Conservancy. The initiative is organized as South Mountain Partnership, which involves other organizations, government, business, and community members.

History
The history of South Mountain defines the early history of western Maryland. It was viewed as a boundary to the Susquehannock in their original treaty granting land to Maryland. In a 1732 letter to the colonial governor of Maryland, Captain Civility (Togotolisa) chief of Conestoga warns against settlement in the valley beyond the mountain. The first Euromerican land grant west of South Mountain by Maryland was William Park's "Park Hall" in 1731 near Crampton's gap. The earliest route of the Great Wagon Road crossed South Mountain by Fox's Gap on a course between Middletown and Sharpsburg. Other important passes for migration and settlement were Turner's Gap near Boonsboro. Orr's Gap, used today by Interstate 70, and the course of "Cartledge's Old Road" generally following Maryland state route 77. Maryland finally gained clear title to the lands west of South Mountain at the 1744 Treaty of Lancaster. Following the 1859 John Brown's Raid on Harpers Ferry, seven of the raiders escaped from the Kennedy Farm headquarters to Pennsylvania by following (Elk ridge and) South Mountain north. The escapees traveled by night and spent the days in cold camps among the densest thickets they could find along the remote ridge top. They finally left the mountain near today's Caledonia State Park between Chambersburg and Gettysburg, Pennsylvania. The Battle of South Mountain was fought on the mountain at Crampton's, Fox's, and Turner's gaps during the Maryland Campaign of the American Civil War in 1862. In 1863, military engagements of the Gettysburg Campaign on the mountain range included the Fight at Monterey Pass near the Mason–Dixon Line.