In its south section, Cornwall on Hudson rises to the high area known as Deer Hill, a foothill to Storm King Mountain to its immediate south. South of Storm King the town's southeast boundary, with Highlands, leaves the river just north of Crow's Nest and runs through Storm King State Park, taking in most of Black Rock Forest. It turns more southerly, taking in the northwestern sliver of the United States Military Academy Reservation before reaching Cornwall's southernmost point, its tripoint with Highlands and the town and village of Woodbury.