The crash happened Saturday 1:42 p.m. in the 4000-Block of Route 34 near Wolf Road in Oswego, police said.
A 20-year-old man riding a motorcycle eastbound on Route 34 when it crashes into a trailer being towed by a van as it was attempting to turn right into a driveway, police said.
The motorcyclist was taken to a hospital, where he died.
He was identified as Stone Antrim of Oswego.
Police said witnesses reported seeing multiple motorcycles traveling together in the area before the crash and traveling at a high rate of speed.
Investigators said the van involved in the crash was lawfully attempting to turn into a driveway with its turn signal activated at the time of the crash.
No other injuries were reported in the crash.