A wildfire quickly spread after breaking out on the southwest corner of Lake Mathews Monday afternoon, officials said.
The flames were first reported around 4:20 p.m. at the corner of La Sierra Avenue and Cajalco Road, east of Corona city limits, according to Cal Fire Riverside.
The incident was dubbed the Sierra Fire.
Flames were initially reported to be spreading at a “critical rate” and covered about 100 acres within an hour.
But by 6:15 p.m., the flames were 25% contained and covered a total of 110 acres.
As of about 5:40 p.m., there was no immediate threat to structures. The fire was 5% contained.
Cajalco Road was shut down between La Sierra Avenue and Temescal Canyon. Motorists were advised to avoid the area and use an alternate route.
Nearly 175 firefighters were on scene, and three helicopters were also attacking the blaze from the air.
The flames erupted amid strong, gusty winds in the area. However, no red flag warnings were in place in Riverside County Monday evening, despite some being in place in neighboring Los Angeles County.