The fire burning near Mount Aire in Parleys Canyon was said to be only 80 acres Friday, but that was still enough to close a major U.S. thoroughfare and evacuate nearby homeowners.

No structures had been reported damaged or destroyed.

Interstate 80 reopened about 5 p.m. Friday after being closed for most of the day. Kait Webb, a spokeswoman for the Utah Division of Forestry, Fire and State Lands, warned the freeway could shut down again if the blaze worsens or smoke becomes a hazard.

The on-ramps and offramps at ranch Exit 132 and to East Canyon will remain closed.

I-80 closed at 9 a.m. Friday between its junctions with Foothill Drive in Salt Lake City and Jeremy Ranch in Summit County to give firefighters safe access to battle the blaze and to ensure motorists don’t have to contend with flames and smoke.

The Utah Division of Forestry, Fire and State Lands told motorists to detour on Intestate 84 or on U.S. Highway 189 through Provo Canyon. There also were warnings that traffic could increase over Guardsman Pass — the road linking Big Cottonwood Canyon to Park City.

Approximate location of fire

The Parleys Fire had earlier been called 200 acres, but new mapping Friday morning determined it was smaller. By Friday night, it was reported to be 15% contained.

Webb said helicopters were dipping their giant buckets into nearby Little Dell Reservoir and dumping water on the blaze. The reservoir will be closed Saturday and Sunday so firefighters can use it for water, if needed.

Engines from local and federal fire departments were spraying hot spots they could reach.

Firefighters “are extinguishing hot spots within the fire perimeter and are securing containment lines,” Webb said.

The Utah Division of Air Quality warned shifting winds would push the wildfire smoke into the Salt Lake Valley on Friday night.

Marty Mankins on Friday was driving back and forth between a timeshare he has at Canyons Village in Park City and his home in Murray. What’s normally a 30-minute drive took more than an hour when he had to detour through Provo Canyon, he said. His stepdaughter normally works in downtown Park City but did her job at home Friday.

“It’s usually an easy drive up or out,” Mankins said, “and now it’s trying to find the best route without it taking the rest of your day.”

Authorities are looking for a dump truck dragging chains that reportedly drove through the canyon Thursday. Anyone with information about the truck can call investigators at 801-538-5418.

About 250 homes in the vicinity of Mount Aire have been evacuated, Webb said. An evacuation center at Skyline High School was closed Friday. Anyone needing assistance can call the Red Cross at 800-733-2767.

Correction: Correction at 11:07 a.m.: An earlier version of this article referred to Guardsman Pass as a dirt road. The last dirt section of the road was paved in 2018.