N.Y. Town Law § 270
The town board may establish an official map of that part of the town outside the limits of any incorporated city or village showing the streets, highways and parks theretofore laid out, adopted and established by law and drainage systems may also be shown on such map. Such map shall be final and conclusive with respect to the location and width of streets and highways, drainage systems and the location of parks shown thereon. Such official map is hereby declared to be established to conserve and protect the public health, safety and general welfare. The clerk of every town which has established such an official map shall immediately file a certificate of that fact with the clerk or registrar of the county in which said town is located.
N.Y. Town Law § 270