The blaze jumped the Sunrise Highway in the Julian area in early afternoon and by sunset it had damaged or destroyed eight structures, said Roxanne Provaznik, a spokeswoman for the California Department of Forestry and Fire Protection.
Two of the structures were lodges at mountain camps that were destroyed, one at the Al Bahr Shrine Camp and another at a Sierra Club camp.
It was not immediately clear what the other six were.
The wildfire, which started Saturday, forced about 30 people from campgrounds in the Cleveland National Forest and from rural homes, state fire spokesman Mike Mohler said.
Mohler said the flames threaten 120 buildings, though most are unoccupied vacation cabins.
Crews could face 107-degree heat and 30-mph winds in the afternoon.
Nearly 1,200 firefighters, aided by 18 aircraft and seven bulldozers, were sent to battle flames in thick brush as winds gusted and temperatures flirted with triple digits. The rocky terrain is so steep that some crews were ferried in by helicopter.
Four firefighters had minor injuries.
In Malibu, Calif., cleanup has started for a 1.5-acre brush fire that broke out on Castro Peak Monday morning.
The city's emergency services said firefighters were able to knock out the flames on Castro -- one of the highest peaks in the Santa Monica Mountains -- within an hour.
There were no injuries or damages and the cause of the fire is under investigation.
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