Burlington Northern Santa Fe spokesman Gus Melonas says the train from Portland was headed to Vancouver, British Columbia, and hit the man about 200 yards north of the crossing at 172nd Street.
The crew saw the man carrying a bicycle in the middle of the tracks, but was unable to stop in time to avoid hitting him.
Shortly afterward, the 118-car train came to a stop. Officers responded and have blocked 172nd Street for a death investigation.
Melonas said a second person was with the victim and left to get coffee before the accident. Both of them reportedly live in the area.
Melonas says it's the 19th fatality this year on BNSF tracks in Washington. There were two other deaths just last Friday at Edmonds and Auburn.
The Marysville accident delayed three freight trains waiting for the track to be reopened about 7:30 a.m.