 New York State Route 421 | ||||
|---|---|---|---|---|
 Map of the Tupper Lake area with NY 421 highlighted in red, former NY 421 extension in pink, former NY 971D in grey | ||||
| Route information | ||||
| Maintained by NYSDOT | ||||
| Length | 5.70 mi[1] (9.17 km) | |||
| Existed | c. 1931[2][3]–present | |||
| Major junctions | ||||
| West end | Dead end at Horseshoe Lake in Piercefield | |||
| East end |  NY 30 in Piercefield | |||
| Location | ||||
| Country | United States | |||
| State | New York | |||
| Counties | St. Lawrence | |||
| Highway system | ||||
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New York State Route 421 (NY 421) is a short state highway located within Adirondack Park in the southeastern corner of St. Lawrence County, New York, in the United States. It is a narrow, two-lane spur route connecting NY 30 to Horseshoe Lake by way of Tupper Lake. A dead end sign is posted immediately off NY 30, the only route with which it intersects. The entire road is located in the town of Piercefield, although that name is not posted on NY 421. The route offers access to several picnic and snowmobile areas.
The eastern portion of NY 421 was built in the 1920s under the terms of a 1923 law authorizing the construction of a highway leading from modern NY 30 north to Warren Point. This road was completed in 1925. NY 421 was assigned to the entirety of the north–south highway c. 1931. The roadway connecting Horseshoe Lake to Tupper Lake was built in 1961 on a former alignment of the Delaware and Hudson Railway. NY 421's former routing to Warren Point remained a state highway up through 1999, when a bill permitting the New York State Department of Transportation (NYSDOT) to remove it from the state highway system was signed into law.