In 1924, the segment of the Theodore Roosevelt International Highway within New York was designated NY 3. At that time, it spanned the full east–west length of the state, extending from the eastern bank of the Niagara River in North Tonawanda to the western edge of Lake Champlain in Plattsburgh; however, the routing through the North Country was significantly different at that time from its modern alignment. The route was moved onto its modern routing east of Watertown as part of the 1930 renumbering of state highways in New York; it was truncated to Sterling on its western end and rerouted to follow its current alignment from Sterling to Watertown roughly five years later.