New York State Route 104

New York State Route 104 (NY 104) is a 182.41-mile (293.56 km) long east–west state highway in Upstate New York in the United States. It spans six counties and enters the vicinity of four cities—Niagara Falls, Lockport, Rochester, and Oswego—as it follows a routing largely parallel to that of the southern shoreline of Lake Ontario, along a ridge of the old shoreline of Glacial Lake Iroquois. The western terminus of NY 104 is at an intersection with NY 384 in Niagara Falls, Niagara County, while its eastern terminus is at a junction with NY 13 in the town of Williamstown, Oswego County. The portion of NY 104 between Rochester and the village of Webster east of the city is a limited-access highway known as the Keeler Street Expressway west of NY 590 and the Irondequoit–Wayne County Expressway east of NY 590; from Williamson to Oswego, NY 104 is a super two highway.

The majority of Ridge Road and modern NY 104 from the village of Red Creek to the town of Mexico were originally designated as part of Route 30, an unsigned legislative route, early in the 20th century. All of Ridge Road and its continuation through Oswego to the hamlet of Maple View gained a signed designation by 1926 and became part of U.S. Route 104 (US 104), a United States Numbered Highway extending from Niagara Falls to Maple View, c. 1935. US 104, which never connected to US 4, its implied parent route, was redesignated as NY 104 c. 1972. As part of the redesignation, NY 104 was extended east to NY 13 in Williamstown over what had been New York State Route 126.