Updated, 8:20 a.m. Saturday.

A fast-moving wildfire that sparked late Friday afternoon in northern Utah forced sudden evacuations and shut down a portion of Interstate 15.

The closure hit on one of the last Friday evenings of the waning summer 2026 season, which can make for a particularly busy travel day.

By 6 p.m., the Harley Fire was estimated between 150 and 300 acres, more than doubling in size less than an hour after it started, according to state fire officials. It’s burning along I-15 in Box Elder County, north of Tremonton and west of Garland.

Fire officials said Friday evening that structures were threatened, though it wasn’t immediately clear how many. And infrastructure, including power lines and water systems, were also at risk.

The Garland Fire Department has ordered all residents in the city around Harley Drive to evacuate immediately. The department placed the Radio Hill area on “ready” status, meaning they need to prepare to leave quickly if called for.

The evacuation order for Harley Drive and the “ready” order for Radio Hill both remained in effect Saturday morning, Box Elder County government reported on its Facebook page.

An evacuation center has been opened at Garland Armory, 72 N. Main Street, where the city fire department is stationed.

Power was shut off in the affected area, with outages across Tremonton and Garland.

I-15 was initially closed in both directions from mile markers 381 to 385. That’s near 1000 North, which is near Tremonton, according to the Utah Department of Transportation. Northbound traffic reopened about 7 p.m., and southbound lanes were reopened by 9 p.m., Utah Fire Info reported.

The fire is burning through dry grasses, officials say, with hot and windy conditions causing it to spread quickly. When the fire was initially reported around 5 p.m., it measured at about 75 acres.

“We ask that the public stays away from the area to allow emergency personnel and drones to work efficiently,” the Garland Fire Department wrote in a Facebook post.

By 7 p.m., fire officials reported having established a dozer line around the perimeter of the blaze that was helping to keep the fire contained while crews braced for strong gusts from an approaching storm.

Two other wildfires also started in Box Elder County late this week, including one in Hansel Valley, where the Stratos data center and energy campus is planned.

That blaze, the Salt Wells Fire, started before 6 a.m. Friday. No structures were threatened. By Friday afternoon, it had burned about 585 acres and was considered 60% contained.

A containment figure marks the portion of a fire’s perimeter where crews are confident the flames won’t cross. Fire officials determined it was human-caused.

The separate Little Mountain Fire sparked Thursday afternoon, burning north of the Bear River Migratory Bird Refuge and south of Tremonton. By Friday, it had reached 560 acres and was considered 75% contained, according to fire officials. A cause has not been listed.

This is a developing story and will be updated.