Cal Fire urged about 50 households who have not yet evacuated to do so, saying the worst may not be over, and that remaining endangers their lives as well as the safety of firefighters.
Last week, an extended period of extreme heat worsened fire conditions and threatened the state's power grid as demand hit an all-time high, but the weather turned cooler over the weekend.
The power company PG&E Corp said last week that there had been electrical activity near one of its transmission poles in the area around Oxbow Reservoir where the fire started. The company also said that the U.S. Forest Service had placed caution tape around the base of the pole.