A brush fire burned more than 7 square miles Monday, tripling in size overnight, near Pilot Rock Ridge above Silverwood Lake in the San Bernardino National Forest.
Fire officials evacuated areas around Highway 138 and Old Mill Road, and around Highway 138 and State Route 173. Additional evacuations were ordered at 5 p.m. in the Summit Valley area east of Cedar Springs Dam.
More than 300 San Bernardino County Firefighters were battling the blaze, which began Sunday, along with seven air tankers. Firefighters battled overnight and containment reached 5 percent.
"The biggest threat is that we're working with very dry vegetation that hasn't burned in a long time," said Eric Sherwin, of the San Bernardino County Fire Department. "We've seen that all through the day, yesterday, and during the overnight hours."
California is in its fifth straight year of drought, leaving hillsides and other areas covered in brush primed for wildfires. Firefighters said the state could be facing one of its worst fire seasons on record.
The Pilot fire also caused air quality problems throughout the region.
Smoke plumes roiled from ridges of the San Bernardino Mountains and blew all the way across the Mojave Desert to Las Vegas. Across the Mojave, officials in southern Nevada issued an air quality advisory because of smoke from the fire more than 200 miles away. The Clark County Department of Air Quality said air was unhealthy for sensitive groups, including young children, senior citizens and people with respiratory problems and cardiac disease.
Like some of the state's other fires this summer, the blaze burned near a popular recreation area. But Silverwood Lake's waters had been closed to swimming, fishing and boating since Aug. 4 because of an algae bloom.
Another 12 engines, two crews, two tenders, one dozer and three chief officers had also been dedicated to the efforts.
Road closures were in place between Highway 138 and State Route 173.