A 37-year-old Arroyo Grande man sustained major injuries when the motorcycle he was driving drifted off Huasna Road and ran into a creek bed, the CHP said.
Upon hitting the dry creek bed, the man was ejected from the 2005 Suzuki motorcycle.
The accident occurred at 7:05 p.m. Thursday as the man headed west on Huasna Road, west of Santa Domingo Drive, the CHP said.
"Alcohol is suspected as being a factor in this traffic collision," the CHP said in a news release.
The man was not identified by the highway patrol.