A fire ignited yesterday and spread quickly in the area south of Lake Berryessa in Napa and Solano Counties, and it grew overnight to burn about 6,000 acres, fire officials say. As the Chronicle reports, around 500 firefighters are fighting what is being called the Wragg Fire, working to protect about 200 structures in the area amid evacuations.

“It was a difficult night overnight,” said a spokeswoman for Cal Fire. “The winds have been definitely hampering efforts — it was breezy all night.”

The evacuations were for two unincorporated communities at the Lake's southern end: Quail Ridge near the Markley Cove Resort in Napa County, and Golden Bear Estates in Yolo County west of Winters. An evacuation center was set up in Winters. Two campgrounds were also cleared and three hikers in the area were rescued by helicopter.

ABC7 reports that the flames first appeared around 2:30 p.m. near Highway 128 at the south end of Lake Berryessa.

Although Cal Fire officials at first said the blaze was caused by a vehicle catching fire after an accident, they have since said they are investigating the cause further.

While firefighters work from the ground, air tankers are performing water and fire retardant drops. Winds and steep terrain have made the fight particularly difficult. And, in the ranching area, livestock are in danger.

The fire resembles one from last summer in the same area. Then, a 6,500 blaze known as the Monticello fire was sparked by July 4th fireworks.

Update: As the LA Times reports, though it destroyed two buildings and at one point swelled to over 8,000 acres, the fire is now 80% contained.