WHAT DID HAPPEN ON TOP OF THAT ROCKY HILL? TERRAIN, GEOLOGY, AND HISTORICAL UNCERTAINTY AT THE BATTLE OF MINISINK (1779), NEW YORK-PENNSYLVANIA

On July 22, 1779, two days after raiding the frontier settlement of Minisink (Port Jervis, NY), a band of Indians and Tories under the Mohawk Col. Joseph Brant decimated a pursuing force of New Jersey and New York militia in a bloody fight at Minisink Ford in present-day Sullivan County, NY. Though much has been written on the Battle of Minisink, the events of that horrific day are shrouded in uncertainly. The causes of this historical confusion can largely be traced to conflicting accounts in early recollections, to the poor quality of battleground maps in many subsequent writings, and to the fact that the wilderness site lay neglected for 43 years before the bodies of the slain militiamen were recovered.

The Minisink battleground is preserved as a county park near the top of a flat-topped hill 500 feet above an enclosing right-angle bend of the Delaware River opposite Lackawaxen, PA. Bedrock at the site consists of gently north-dipping, planar- and crossbedded sandstones of the Lackawaxen Member of the Late Devonian-age Catskill Formation. The upper east face of the hill, where most of the battle was apparently fought, consists of four topographic steps formed by sandstone ledges 10 to 20 ft high. The orientation of the ledges is controlled by subvertical north-south bedrock joints. The ledges step down to the valley of a small spring-fed stream that descends in a southeast direction to the Delaware.

Terrain and geological features that had an impact on the most probable battle scenario include the Minisink ford (localized the action at a strategic Delaware River crossing), the spring-fed ravine (allowed a party of Brant’s men to come up behind the militia early in the fight), the bedrock ledges (controlled the later battle lines and gave shelter to the combatants), and "Sentinel Rock" (an isolated residual boulder that, according to tradition, marks the spot where the enemy broke through the militia's final hilltop position).