Utah Highway Patrol officials say 55-year-old Stephen Trottier of La Mirada left the road and hit the tree north of Vernal a little before 5 p.m. Wednesday.
Authorities say his motorcycle flipped and Trottier was thrown 15 feet.
Troopers say Trottier was flown to a hospital but died early Thursday morning.
Officials say it's not clear why Trottier went off the road.
(Copyright 2012 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)