Cal Fire rallied firefighters and five aircraft to put out a quick-spreading blaze that was sparked Sunday afternoon by a motorcycle in the hills east of Dulzura.
No structures were damaged or threatened by the brush fire that burned east of the historic Clark Ranch about 45 miles east of San Diego. Cal Fire initially said it had burned 27 acres but later said it scorched six acres.
While crews battled the blaze, state Route 94 was closed between Summit Road, just east of Barrett Junction, to the state Route 188 cutoff to Tecate, near where the fire started.
Dubbed the Barrett fire, it started about 1:15 p.m. when a motorcycle's hot underside ignited brush after leaving the paved roadway. The motorcyclist was not injured, Cal Fire spokesman Kendall Bortisser said. The fire was extinguished about two hours later.
Dispatchers sent 15 engines, a bulldozer, three hand crews, two water tenders, two air tankers, two helicopters and one fixed-wing observation plane.
The fire had surrounded but did not damage the city of San Diego's old Dulzura flume, Bortisser said. It carries water from Barrett Lake to the Sweetwater Reservoir near Chula Vista, which was San Diego's sole municipal water supply in the first part of the 20th century.
