A fire ignited in the San Jacinto Mountain between Hemet and Idyllwild on Sunday and quickly blackened more than 163 acres within the San Bernardino National Forest, authorities said.
The Bautista Fire was first reported around 7 p.m. in the forest east of Hemet and south of Idyllwild, prompting the closure of Bautista Canyon Road, according to San Bernardino National Forest officials.
No structures were threatened, and no evacuations were ordered, officials said. But U.S. Forest Service officials noted that the fire appeared to have "potential" to spread to 500 acres or more.
More than 150 firefighters, assisted by a night-flying helicopter, continue battling the flames Sunday night.
Cal Fire firefighters joined their counterparts in the U.S. Forest Service in fighting the fire.
The cause of the fire was under investigation.