NY 21A
NY 21A was an alternate route of NY 21 along the eastern side of Canandaigua Lake. When it was assigned as part of the 1930 renumbering of state highways in New York, it began at NY 21 north of the village of Naples and ran along the east shore of the lake to eastern Canandaigua, where it ended at US 20 and NY 5. In between, NY 21A passed through the lakeside hamlet of Vine Valley. The route was truncated c. 1939 to begin in Vine Valley, separating it from its parent route. It was eliminated entirely in the early 1940s when most of NY 21A was absorbed by NY 364.
Read more about this topic: New York State Route 21