A day after it erupted near Lake Elsinore, the fire had blackened more than 2 square miles and was 30 percent contained, the U.S. Forest Service said.
Residents in the small community of Decker Canyon were told they could return home after evacuations for most areas, including the much larger Lakeland Village, were called off a night earlier.
But fire officials warned that danger remained.
"Residents need to keep their heads up" in case the fire flares up, state fire spokeswoman Julie Hutchinson told KNX-AM.
Gov. Jerry Brown announced Tuesday that the state has secured a federal fire management grant to help local, state and tribal agencies with the cost of the fire.
The blaze burned a barn and damaged another outbuilding shortly after breaking out Monday in the Cleveland National Forest, about 70 miles southeast of Los Angeles. The cause was unknown. It sent hazy smoke and a drizzle of ash over nearby communities.
About 1,000 firefighters fought the blaze with the aid of aircraft, including a giant DC-10.
Televised news reports showed fire trucks on a road flanked on both sides by spot fires and walls of flame.
Firefighters reported only a few minor injuries.
Another small fire broke out Tuesday about 50 miles away near the Palm Springs Aerial Tramway, burning through about 60 acres of light brush.
Steep terrain meant the fire was mostly being handled by hand crews and water drops from the air. It was 20 percent contained.