Marin County fire officials said the "Bolinas Fire" was fully contained at about 5 p.m.
According to Marin County fire Battalion Chief Mike Giannini, crews first responded to a report of a fire in the trees along the Bolinas-Fairfax ridgeline between Kent and Alpine lakes just after 9 p.m. Friday.
Cool temperatures overnight helped firefighters tame the fire in the tough terrain, Giannini said.
The chief said the area's dense vegetation made it "difficult to access and subsequently extinguish all of the hot spots." /P>
No injuries have been reported and there are no buildings in the area, authorities said.
Crews from Marin County, Ross Valley, Bolinas Volunteer fire departments, and Cal Fire battled the blaze.
The California Highway Patrol and Marin County Sheriff's Office provided traffic and air support for the fire crews.
(ABC7 News contributed to this report)