Several DC-10 jets have been pressed into service to douse the wildfire that has grown to 15,500 acres (6,272 hectares) in a southern California coastal mountain range, according to reports.
The jets dropped fire retardant over the western flank of the massive fire along the southern California coast on Thursday, but firefighters continue to face impediments to contain it.
The Alisal Fire, which broke out on Monday about 20 miles northwest of Santa Barbara in a sparsely populated corner of southern California, has engulfed a massive area and remains just 5 percent contained as of Thursday, according to Andrew Madsen, a spokesman for Los Padres National Forest.
“The further this fire moves both east and west it will move into some fire scars from previous wildfires, so those areas aren’t going to have nearly the amount of fuels for the fire to work with,” Madsen was quoted as saying.
It has destroyed more than 26 square miles (67 square kilometers) of chaparral and grass in the Santa Ynez Mountains west of Santa Barbara since it erupted Monday amid high winds.
A crew of roughly 1,500 firefighters have so far steered the wildfire away from the Reagan ranch, where the former US President Ronald Reagan hosted many world leaders.
The blaze has been centered within a half mile of Reagan's ranch, reports said.
California is on pace to suffer more burnt acreage this year than last, the worst fire season on record when 4.2 million acres (1.7 million hectares) went up in flames – an area the size of Hawaii.
California Governor Gavin Newsom said on Wednesday the state had secured federal funds to reimburse 75% of local and state costs related to fighting the blaze.
California wildfires have scorched nearly 3,900 square miles (10,101 square kilometers) this year and destroyed more than 3,600 homes, businesses and other structures, according to the state Department of Forestry and Fire Protection.
A historic drought in the American West tied to climate change is making wildfires harder to fight.