The Traverse fire was burning in the Traverse Mountain area, near the city of Lehi, fire officials said.
Strong, gusty winds quickly spread the flames over 150 to 200 acres.
Thirty homes have already been evacuated and evacuation orders are increasing, said Utah Fire Info. Evacuation centers are open to house people forced to leave their homes.
Multiple power outages are reported in the fire area, said the Utah division of emergency management on Twitter.
Firefighters plan to bring heavy equipment so they can start building containment lines, said the fire officials.
A fireworks suspect who started the forest fire is cooperating with law enforcement, officials said.
Fire officials noted on Twitter that the rejection of fireworks is prohibited in Utah, except during certain periods, including July 4 and New Years Eve.
