The fire has burned 2,190 acres since it erupted around 8 a.m. Wednesday near the North Etiwanda Preserve, according to Cal Fire. As of Saturday afternoon, it was 86 percent contained.
One structure was damaged by the blaze. In the middle of fierce Santa Ana winds, the fire also threatened 1,650 foothill homes, forcing evacuations.
The winds also fanned a handful of small brush fires around Southern California that were quickly doused without damage.
According to the San Bernardino National Forest, firefighters constructed a line around the burn on the northern side, while aircraft made drops in the tough terrain.
At least 580 personnel from the U.S. Forest Service, CAL FIRE, Ranch Cucamonga Fire Protection District and San Bernardino County Sheriff's Department are assisting in the firefighting efforts. Three firefighters suffered minor injuries.
The cause of the fire remains under investigation. The North Etiwanda Preserve remains closed to visitors.
