A brush fire erupted Wednesday on the southeast end of the Lake Perris State Recreation Area, burning over 100 acres in an hour but not immediately threatening structures.
The non-injury blaze was reported at 2:35 p.m. near a landmark called Pictograph Rock, along the Loop Trail, according to the Riverside County Fire Department.
The agency said multiple engine and hand crews were sent to the location and encountered flames amid rugged terrain in the preserve.
Officials at the scene estimated the blaze to be 107 acres as of 3:45 p.m.
Three Cal Fire water-dropping helicopters and an air tanker initiated runs on the brusher just after 3 p.m.
Winds were pushing the flames to the southeast at an expeditious rate, away from campgrounds but in the direction of the Lakeview community.
It was not immediately clear what triggered the fire.