A wildfire in Napa County that had threatened up to 50 homes on Friday and destroyed one outbuilding has been largely contained, with firefighters strengthening their lines and performing mop-up operations around the blaze.

Dubbed the Silverado fire, it was burning east of Napa and remained at 300 acres at 2 p.m., with 80 percent containment and 150 firefighters assigned.

The fire, first reported late Thursday, spread through oak forest and grassland in the hills east of Silverado Trail. It threatened homes in the Soda Canyon Road area, triggering an evacuation order that was lifted just before 6 p.m. Friday.

The cause of the blaze was under investigation, though law enforcement officials said downed power lines were suspected.