A brush fire that erupted Monday on the north end of Lake Mathews, just south of Riverside, was mapped at 34.5 acres and was 70% contained.
The non-injury blaze was first reported at 10:40 a.m. in the area of La Sierra Avenue and El Sobrante Road, according to the Riverside County Fire Department.
The agency said multiple engine and hand crews from the county, Corona Fire Department and other agencies were sent to the location and encountered flames moving rapidly across dry grass, with northerly winds gusting at more than 20 mph.
Sheriff’s deputies shut down La Sierra in both directions for public safety.
Three Cal Fire air tankers and a water-dropping helicopter made a series of runs on the brusher that blunted the head and prevented it from crossing roads, enabling crews to establish tentative containment lines.
At noon, the forward rate of spread was stopped.
Although the blaze was in an open field, it briefly veered toward two remotely located properties, which were initially placed under an evacuation order. However, that was downgraded to a warning at 12:10 p.m.
By 2:12 p.m., the fire was mapped at 34.5 acres and was 70% contained, fire officials said.
The cause of the fire was under investigation.