BIG BEAR LAKE  (AP) — Crews working amid sweltering conditions in rough terrain have slowed the spread of a huge forest fire that’s churning through timber in a remote area of the San Bernardino Mountains.

The U.S. Forest Service said Sunday that the blaze in old-growth wilderness east of Los Angeles is holding steady at 25 square miles. The fire is 15 percent contained as it pushes east toward the Mojave Desert.

About 400 buildings, including old cabins, are threatened but none have been lost.

Meanwhile a blaze that burned at least two homes near Santa Margarita, northeast of San Luis Obispo, has grown to 1.8 square miles.

Helicopters were taking water from Santa Margarita Lake to dump on the blaze, which is 15 percent contained.

Several hundred residents were evacuated at the height of the fire Saturday afternoon.