A wildfire along northern California’s inland coastal range has now burned nearly 46,000 acres (18,615 hectares) and forced the closure of two highways, officials said on Sunday, after a second blaze near the Oregon border killed a firefighter.

The Rocky Fire in Lake County north of San Francisco has grown in size by about 20,000 acres (8,094 hectares) since Saturday, according to Cal Fire, a state website for fire information.

The fire has closed parts of Highway 20 and Highway 16, destroyed 24 homes and 26 more outbuildings, and threatens an additional 6,301 structures, according to Cal Fire.

Nearly 2,000 firefighters are battling the fire, which broke out on Wednesday and is only 5 percent contained, the same percentage as on Saturday, according to the website. About 12,000 people have been evacuated or are under evacuation advisories.

Drought-stricken brush and grasslands have made parts of California vulnerable to wildfires.

Among numerous fires burning in the state is the Frog fire, which officials said killed a firefighter on Thursday. David Ruhl, 38, a married father of two from Rapid City, South Dakota, died while assigned to the fire in the Modoc National Forest near California's border with Oregon.

Ruhl was alone and working as incident commander on the fire, said Modoc National Forest spokesman Ken Sandusky. It is common for a leader on a fire to travel alone, Sandusky said, but he declined to release more details on the death.

The Frog Fire is about 5 percent contained, has grown to 3,000 acres (1,214 hectares) and erratic winds have pushed it in all directions, according to the U.S. Forest Service's InciWeb online fire information center.

No updates on the fire were posted on the Forest Service website on Sunday and officials could not be reached for comment.

A red-flag warning, designating the threat of gusty winds that risk fanning flames, was expected to remain in effect until late Sunday in the area of the Frog Fire. InciWeb said the flames are not expected to be fully under control until Aug. 12.

(Reporting by Kevin Murphy in Kansas City; Additional reporting by Alex Dobuzinskis in Los Angleles; Editing by Catherine Evans)