Troopers say 65-year-old Frank Clark Jr. rear-ended a box truck waiting at the intersection of Mount Baker highway and Marshall Hill road.
Witnesses tell troopers Clark was going the speed limit of about 45-miles-per-hour at the time of the crash.
Troopers say drugs and alcohol do not appear to be a factor.
Clark was thrown from his motorcycle and died at the scene as a result of his injuries.
The 34-year-old box truck driver from Mount Vernon was not injured.
