Evacuations were underway in the Summit Valley area east of Cedar Springs Dam.
According to the San Bernardino County Sheriff's Department, mandatory evacuations were ordered for Arrowhead Lake Road, south of Hesperia Lakes to Highway 173.
Highway 173 was closed between State Route-138 and Arrowhead Lake Road. Highway 138 was closed from Old Mill Road to Highway 173, but has since reopened.
Smoke advisories were issued by health officials for the Mojave Desert area.
What started as a 30-acre brush fire quickly grew to nearly 1,500 acres by Sunday evening, according to the San Bernardino National Forest.
San Bernardino County fire officials said the blaze, dubbed the Pilot Fire, was burning north with southwest winds.
Forest fire officials said about 400 personnel were assigned in the fire fight.
It was not immediately clear what sparked the blaze.
Those with questions regarding the Pilot Fire were urged to call the San Bernardino Fire Information Center at (909)383-5688.
The American Red Cross moved its evacuation center from Ranchero Middle School to Oak Hills High School, located at 7625 Cataba Rd.
Those with large and animals can take them to Devore Animal Shelter, located at 19777 Shelter Way in San Bernardino.
Several Eyewitness News viewers reported seeing the fire and shared photos using #abc7eyewitness.
DEVELOPING: We will add more details to this report as they become available.