The name of the victim has been withheld pending notification of family members, the sheriff's department said in a statement.
It said a GMC Yukon was headed west on the state highway about 5:10 a.m. in heavy fog, about half a mile east of County Road 100 East, when it attempted to pass a commercial motor vehicle not involved in the crash.
During the passing attempt, it said, the Yukon collided head-on with a Harley Davidson Electra Glide headed east on the state highway.
Both vehicles and occupants left the roadway, the statement said. It said the motorcyclist died at the scene; the Yukon's driver suffered minor injuries.
The crash investigation is continuing, the statement said.