The man -- who responders said appeared to be in his 20s -- was struck near the Clinton Avenue crossing off Briarwood Lane near Veterans Memorial Park shortly after 9 p.m. Wednesday, Jan. 3.
Northvale police officers who were called by a CSX employee found the victim face down along the tracks south of the crossing, Northvale Police Chief Howard J. Ostrow said.
He had no pulse, wasn't breathing and was pronounced dead at the scene via an Advanced Life Support unit a short time later, the chief said.
The Bergen County Medical Examiner took custody of the body, Ostrow said.
There was no immediate official word on what the man may have been doing on the tracks near the crossing, which is roughly a half-mile south of the New York State border in Tappan.
CSX police are investigating.
Click here to follow Daily Voice North Hunterdon and receive free news updates.