CHP officials say a male driver was airlifted to Cottage Health in San Luis Obispo after crashing his motorcycle on Northbound Highway 101 Sunday.
It happened just after 6 p.m. near Clark Avenue, CHP says.
Witnesses told deputies the driver appeared to have been going a high rate of speed and may have hit something in the road.
Drugs or alcohol do not appear to be factors in the crash, deputies say.