Interstate 81 enters the state of New York near Binghamton. It follows U.S. Route 11 in a north–south direction, through much of the state. It serves the cities of Syracuse (where it intersects the New York State Thruway), and Watertown. The route ends at the Canadian border at the Thousand Islands Bridge, where it crosses the St. Lawrence River, continuing as a short connector, Highway 137, which serves the Thousand Islands Parkway and Highway 401.