After a morning muster, on July 15, the Corps of Light Infantry marched from Sandy Beach north of Fort Montgomery beginning at noon. Any civilians met along the route of march were to be taken into custody to prevent them from warning the British. The column, often forced to march single file over rough terrain and roads hardly more than paths, took a circuitous route west through Queensboro to the west and over Dunderberg Mountain to avoid detection by the British. The Corps began arriving at 8 p.m. at the Springsteel farm, a mile and a half (2 km) west of the fortifications, and by 10 p.m. had been formed in the attack columns.