RODEO (CBS SF) — A wildfire erupted Saturday afternoon near the refineries in Rodeo and burning to the edge of I-80 forcing the closure of a freeway off-ramp and charring more than 200 acres, authorities said.

The fire erupted at around 3 p.m. near I-80 just passed the Willow Ave. off-ramp. By 6 p.m. it had grown to 250 acres and was 25 percent contained.

Authorities said there were no structures being threatened by the blaze but the it did force the closure of the Cummings Skyway.

Firefighters from several agencies battled the blaze. Calfire air tankers and helicopters were also used to battle the flames and halt the spread of the fire.

The California Highway Patrol said to avoid the area if possible.