Police determined that Frank Moreno, 49, was struck by two vehicles around 6:45 p.m.
Moreno, of Santa Rosa, was knocked off his bicycle when he was struck in the southbound lane of Fulton Road just south of Chatham Road, Sgt. Lance Badger said.
That vehicle left the scene before police arrived, Badger said.
Moreno was then struck by a second southbound car as he was lying in the roadway, Badger said. That driver, Bianca Belle-Bonas, 18, of Santa Rosa, stopped at the scene, Badger said.
Moreno was pronounced dead at the scene, although it is unclear which collision caused his death, Badger said.
Police said the vehicle that fled the scene was a silver late 90s or 2000-model Dodge Durango or Dakota. The SUV may have damage from the collision.
Police are still investigating the incident. Anyone with information on the case is asked to call Officer Mike Mieger at (707) 543-3636.