From Easton and Wyoming to the Genesee Castle: terrain and military geology along the route of “Sullivan’s March” (1779), Pennsylvania and New York

Inners, Jon D. (retired), Pennsylvania Geological Survey, 3240 Schoolhouse Road, Middletown, PA 17057, and Howe, Richard H., 2911 Chestnut Street, Camp Hill, PA 17011

The punitive expedition of Major-General John Sullivan against the British-allied Iroquois Confederacy in 1779 was the outstanding example of  “total war” in the American Revolution.  Sullivan and his army marched 250 miles into hostile territory in north-central Pennsylvania and western New York, destroying at least 40 villages, burning hundreds of acres of crops, and defeating the Indians and Tories at Newtown, NY, in the only pitched battle of the campaign.  The progress of “Sullivan’s March” is well described in the many journals kept by participating officers and men.

Sullivan’s main army followed Indian trails in making a physiographic transect from the Great Valley to the Genesee River—across Blue Mountain, the Pocono Plateau, the Lackawanna basin, and the glaciated Allegheny Plateau.  The route made use of such landscape features as the Wind Gap, the North Branch Susquehanna River valley, and the east side of Seneca Lake.  Another brigade under Brig.-General James Clinton followed the North Branch on the Allegheny Plateau from Lake Otsego, NY, to a junction with Sullivan at Tioga Point (Athens), PA.  The campaign journals provide descriptions of the terrain traversed by both forces and of many individual geologic features observed en route, e.g., waterfalls (Spring Falls near Pittston, PA, Buttermilk Falls at Falls, PA, and those at Watkins Glen, NY), the western Finger Lakes (from [Cayuga] to Conesus), and the monolithic Standing Stone on the North Branch south of Towanda, PA.

Terrain and geologic conditions had a major impact on the Battle of Newtown, fought on the banks of the Chemung River south of Elmira.  In achieving victory, the American forces routed the enemy from a strong defensive position behind an esker and a swamp, bounded by the river on the west and a steep mountain spur on the east. 

Though the military significance of Sullivan’s campaign is a matter of argument, its social and economic importance is beyond dispute.  It depopulated a large tract of Indian country just beyond the frontier and introduced a host of land-hungry Americans to the rich bottomlands of the upper North Branch Susquehanna, the Chemung, and the Genesee.  The soldiers’ journal entries undoubtedly reflect the verbal reports to families and neighbors that spurred a post-war influx of settlers into the former Iroquoian homeland.

Poster paper presented at the 38th Annual Meeting of the Northeastern Section Geological Society of America, Halifax, Nova Scotia, March 27, 2003.


Inners, Jon D., and Howe, Richard H., 2003, From Easton and Wyoming to the Genesee Castle: terrain and military geology along the route of “Sullivan’s March” (1779), Pennsylvania and New York: Geological Society of America Abstracts with Programs, v. 35, no. 3, p. 8.