A 53-year-old Merced man was killed early Tuesday afternoon when his pickup crossed Merced Falls Road and struck a tree, the California Highway Patrol reported.
CHP officers did not release the man's name pending notification of his family.
They said a passenger in the truck, Garland Barnes, 65, of Merced, was taken to Modesto's Memorial Medical Center for treatment of moderate injuries.
Officer Jason Schoonhoven, CHP spokesman, said the accident took place at about 12:18 p.m. on Merced Falls Road east of La Grange Road. The driver was pronounced dead at the scene.
Schoonhoven said it's unknown why the driver allowed his vehicle to drift to the left, across the westbound lane of Merced Falls Road, and onto the dirt shoulder of the road.
He said the driver lost control and the left side of the truck hit a tree on the north side of the road.
It's unknown if alcohol was a factor in the accident, which remains under investigation, Schoonhoven said.