BRIAN HEAD, Utah (AP) — A wildfire has forced the evacuation of hundreds of people from a ski town in southwestern Utah and a highway has been shut down as more than 100 firefighters battle the flames.

Fire officials say the wildfire near Brian Head was human caused, and grew from 50 acres to 500 acres Saturday. Ground crews worked to protect homes and structures while helicopters and planes dropped fire retardant near the perimeter to slow the growth of the blaze. Firefighters reported no containment.

Some 750 people were evacuated by late Saturday, and Highway 143 was closed from Second Left Hand Canyon to Highway 148 near Cedar Breaks National Monument.

Fire managers say extreme heat expected in the coming days will make firefighting efforts even more challenging.

At least two other fires are ongoing in Utah. One in Uintah County is 0 percent contained and has burned about 500 acres. The other is in Piute County and has burned about 350 acres.