A fire burned 3 to 5 acres in Palo Alto's Arastradero Preserve Wednesday afternoon, according to Cal Fire.
Crews were still battling the blaze at about 5:30 p.m., but "all forward progress has been stopped," a Cal Fire spokesman said.
The fire was initially reported at 4:08 p.m. after a caller spotted smoke in the preserve, according to the Palo Alto Police Department.
An area of brush near Arastradero Road between Alpine Road and Page Mill Road was burning when Palo Alto firefighters arrived.
The fire is off one of the trails, and not close to the roadway. No structures were threatened and nobody was injured, according to Cal Fire.
Firefighters with the Santa Clara County Fire Department also assisted with the blaze.
—Bay City News Service