The California Highway Patrol says officers responded to the intersection of Road 140 and Avenue 248 just after 4 a.m. Sunday.
Officers say a man in his 20s was speeding on northbound Road 140 when he ran a stop sign and crashed into a crossing semi-truck.
The man was taken to the hospital with moderate injuries.
The driver of the semi sustained minor injuries.
North and southbound Road 140 was closed for several hours but has since reopened.