Fennell had called the California Highway Patrol for help on his cell phone at 3:09 p.m. Tuesday after his 1998 Harley Davidson went off southbound Highway 1 north of Meyers Grade Road.
He estimated that he was about 15 minutes south of Fort Ross State Historic Park but was unable to give his exact location, the CHP said.
The dispatcher contacted the man's cell phone provider, AT&T, to try to determine his location, and AT&T provided the CHP with a number of positions that were searched from the air using a helicopter and airplane, which eventually had to turn around due to darkness, CHP Officer Peter Van Eckhardt said.
Units from the Sonoma County Sheriff's Office also searched the area on the ground but failed to locate Fennell. A command post was set up at the fire station in Bodega Bay, and a search-and-rescue team was deployed.
The motorcycle was located at about 9:15 p.m. in rough terrain, and Fennell was found and pronounced dead at the scene.
Fennell had veered off the roadway on a slight curve, CHP officials said.
The motorcycle crossed the dirt shoulder and dropped off a steep cliff, with Fennell coming to rest several hundred feet down the steep hillside.
The bike traveled an additional several hundred feet, almost reaching the beach, according to the CHP.
