U.S. Forest Service firefighters along with the San Bernardino County Fire Department responded to the wildfire that broke out just before 11 a.m. near Old Waterman Canyon Road.
The brush fire scorched at least 34 acres and has a rapid rate of spread, according to officials. A heat wave was bringing dangerously hot temperatures to the region Monday, putting fire crews on high alert amid the elevated fire danger.
By around 2 p.m. firefighters said they had stopped the fire's forward rate of spread.
24-acre brush fire erupts in San Bernardino National Forest amid scorching hot temps
A SigAlert was issued for part of Highway 18, which was shut down from Old Waterman Canyon Road and 40th Street to Highway 138.
The public was urged to avoid the area as the brush fire was threatening at least one nearby structure.
It is unclear what caused the fire.
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