The Carstens Fire, burning west of the Yosemite National Park, is human caused, according to investigators.
The fire started as an “escaped campfire.”
Firefighters say there have also been several fires lately caused by barbecues and lawn mowers, combined with dry forest conditions.
The Carstens Fire burned more than 1,600 acres as of Tuesday afternoon and is only 15 percent contained. Eight hundred structures are threatened and several places in the area have been evacuated.