A brush fire erupted Friday in the Santa Ana River bottom along the boundary separating Riverside and Jurupa Valley, propelled by Santa Ana winds that enlarged the blaze to an estimated 40 acres in an hour.
The non-injury “Mission Fire” was reported at 4 p.m. along Mission Boulevard in the middle of the river bottom, just north of Mount Rubidoux, according to the Riverside County Fire Department.
The agency said the flames originated in Jurupa Valley but were pushed into the Riverside city limits within minutes.
Multiple engine and hand crews from the county and Riverside Fire Department were sent to the location and encountered flames moving at a moderate rate to the south amid 10 to 20 mph Santa Ana winds, which began to lose intensity as the afternoon waned.
Two Cal Fire air tankers and three water-dropping helicopters initiated runs on the brusher by 4:45 p.m.
No homes or other structures were in the immediate path of the blaze. However, it was approaching a solar power farm in the area of the Santa Ana River Trail and Tequesquite Avenue, according to officials at the scene.
No evacuation orders were imminent.
The cause of the fire was not immediately known. It was the second one in the river bottom Friday. The first one was stopped at one acre. The area is dotted with homeless encampments, and cooking, warming and debris fires are common year-round.