A fast-moving brush fire broke out Wednesday near Lake Berryessa and spread to 4,000 acres, forcing evacuations and threatening about 150 structures, authorities said.
A vehicle collision near Highway 128 and Greaves Road sparked the blaze about 2:30 p.m., according to the California Department of Forestry and Fire Protection.
Flames spread swiftly through the steep, rugged terrain near the borders of Napa, Solano and Yolo counties, Cal Fire officials said.
Erratic winds posed a challenge to the 400 firefighters deployed to battle the blaze, which has prompted the closure of Highway 128, according to the state fire agency.