West of Plattsburgh, NY 3 exits the park and encounters NY 374 via an interchange. Past the exit, the two routes follow parallel routings before separating outside of Plattsburgh. NY 3 curves to the southeast toward the former Clinton County Airport, where it meets NY 22B just west of what was once the main entrance to the airport. From NY 22B, NY 3 continues east to the outskirts of Plattsburgh, where it meets the Adirondack Northway (I-87). Past I-87, NY 3 follows Cornelia Street into the city, where it becomes city-maintained. Within Plattsburgh, NY 3 intersects NY 22 before terminating at US 9 just west of Lake Champlain.