Firefighters responded Friday night to a small vegetation fire burning in the foothills west of Goleta.

Santa Barbara County crews were dispatched at about 6:45 p.m. to the fire along the 500 block of Farren Road, according to Fire Department spokeswoman Karen Cruz-Orduña.

The fire broke out in mulch piles that had been placed along the roadway, with flames spreading down an embankment, Cruz-Orduña said.

Forward progress of the fire — estimated at a half-acre — was halted shortly after 7:15 p.m., she said.

Extensive mop-up was required due to the amount of mulch in the area, Cruz-Orduña said, adding that firefighters were expected to remain on the scene for at least two hours.

The cause of the fire was under investigation.