NY 256 was assigned as part of the 1930 renumbering of state highways in New York to an alignment extending from Groveland to modern U.S. Route 20A (US 20A) west of Lakeville.

[4] While CR 71 heads northeast toward the hamlet of Conesus, NY 256 continues northwest to serve Scottsburg, a small community in the far northwestern corner of the town of Sparta.

The route continues on, following the western lakeshore through the towns of Groveland and Geneseo as West Lake Road.

At Graywood, a community 1.75 miles (2.82 km) south of the lake's north end, NY 256 joins the Geneseo–Livonia town line and follows it for the remainder of its routing.

[8][9] On April 1, 1983, ownership and maintenance of NY 256 between NY 63 and Depot Road (three blocks north of Perine Street) in Dansville was transferred from Livingston County to the state of New York as part of a highway maintenance swap between the two levels of government.