The body of Charles "Charlie" Dowd, 69, was spotted by a railway worker in Haigler, Neb., an area between Fort Morgan, Colo. and McCook, Neb., the statement said.
Dowd was traveling from Emeryville to Chicago last week, but failed to arrive in Chicago. His cellphone, luggage and medication were found still on the train.
He was last seen by an Amtrak conductor on the train somewhere near Omaha, Neb., according to his wife Patricia.
The conductor told the family that Dowd seemed confused about his whereabouts. The family has said Dowd takes medication that can sometimes leave him disoriented.
The family has conducted a major search effort in the areas along the train's route this past week, following up on possible sightings and contacting media, hospitals and law enforcement in the area. They also created a Facebook page to publicize their efforts.
"While the family is devastated, they would like to express their gratitude for the many prayers, support, and messages posted to the Charlie Dowd Facebook page, and for the efforts of the many volunteers who have helped search for him this past week," the family said in a statement.