Firefighters were working Monday to clear a line of vegetation around an 80-acre brush fire in Thermal that prompted the closure of Highway 86.
The fire was reported around 2:40 p.m. Sunday near the intersection of Avenue 72 and Buchanan Street, according to the Riverside County Fire Department.
Responding firefighters reported the fire burning in heavy fuels at a dangerous rate of spread and additional engines were requested.
At the initial time of report, the fire was burning 40 acres, but had grown to 75 acres just before 5 p.m., when the forward progress was also stopped.
At 9 p.m., fire officials reported that the fire had consumed 80 acres and was 50% contained. Firefighters were going to continue working to clear more vegetation around the fire.
The California Highway Patrol issued a Sigalert for the closure of both directions of Highway 86 near 66th Avenue.
No injuries were immediately reported.
The cause of the fire was unknown.