 In the 1930 renumbering of state highways in New York, the south half of the loop road became part of NY 221, a new route extending from NY 38 at Harford Mills to US 11 in the village of Marathon. NY 221 was extended east to its current eastern terminus in Willet by the following year. The portion of the route between the Harford loop road and Willet utilized a highway added to the state highway system sometime after 1926. NY 221 was rerouted to follow its current alignment to the hamlet of Harford in the mid-1930s, and its former routing to Harford Mills was redesignated as NY 200 in the 1940s.
