A Metro-North maintenance worker found the body inside a culvert two miles north of the train station in the city of Poughkeepsie.
Authorities say police were unable to determine the age, sex or race of the body because of its condition.
Metro-North officials say the Dutchess County Medical Examiner's Office is scheduled to perform an autopsy Thursday.
Metropolitan Transportation Authority police are investigating.
Information from: Poughkeepsie Journal, www.poughkeepsiejournal.com