The Ulster and Delaware Railroad (U&D) was a railroad located in the state of New York. It was often advertised as "The Only All-Rail Route to the Catskill Mountains." At its greatest extent, the U&D extended 107 miles (172 km) from Kingston Point on the Hudson River through the Catskill Mountains to its western terminus at Oneonta, passing through the counties of Ulster, Delaware, Schoharie and Otsego.