New York State Route 3

New York State Route 3
Map of northern New York with NY 3 highlighted in red
Route information
Maintained by NYSDOT and the cities of Watertown and Plattsburgh
Length	245.88 mi[1] (395.71 km)
Existed	1924[2]–present
Tourist routes	Great Lakes Seaway Trail
Major junctions
West end	NY 104A in Sterling
Major intersections	NY 481 in Fulton NY 104 in Mexico I-81 in Watertown NY 86 in Saranac Lake I-87 in Plattsburgh
East end	US 9 in Plattsburgh
Location
Country	United States
State	New York
Counties	Cayuga, Oswego, Jefferson, Lewis, St. Lawrence, Essex, Franklin, Clinton
Highway system
New York Highways Interstate US State Reference Parkways
← NY 2 → NY 3A

New York State Route 3 (NY 3) is a major east–west state highway in New York, in the United States, that connects central New York to the North Country region near the Canada–US border via Adirondack Park. The route extends for 245.88 miles (395.71 km) between its western terminus at an intersection with NY 104A in the Cayuga County town of Sterling and its eastern terminus at a junction with U.S. Route 9 (US 9) in the Clinton County city of Plattsburgh. NY 3 traverses eight counties and is a lakeside roadway from Mexico to Sackets Harbor, a mountainous route in Adirondack Park, and an urban arterial in Fulton, Watertown, and Plattsburgh.

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.

Since 1924, there have been 14 suffixed routes of NY 3, all designated between NY 3A and NY 3G. Of these, all but one only existed during the 1930s. The only active designation is NY 3A, which was assigned in the 1950s to an alternate route of NY 3 in Jefferson County.