A wildfire that forced temporary evacuations and has burned more than 3,000 acres in Provo Canyon was started by an Orem police officer target shooting at the department’s gun range, investigators say.

According to Utah Fire Info, the Orem officer who was “present when the fire started” is cooperating with officials. The officer’s name has not been released.

The Range Fire has more than doubled in size since Sunday, but U.S. Highway 189, which connects Heber City to Utah County, had reopened as of Monday. But parks on either side of the highway are closed temporarily, as well as the Provo River Trail from the mouth of Provo Canyon to Vivian Park and Dry Canyon Trail and Little Baldy/Great Western Trail.

The fire was at 3,450 acres as of Monday morning, up from about 1,500 acres on Sunday morning, fire crews reported.

“Fire activity was minimal overnight,” Utah and federal crews wrote on Twitter. “Growth was significantly slowed by natural features.”

State Road 92 remained closed between Provo Canyon and Cascade Springs, crews reported.

Residents in Provo Canyon and near the canyon mouth were forced to evacuate on Saturday after the fire broke out near an Orem gun range, but they were allowed to return on Sunday.

The fire was about 10% contained, and crews on Monday planned to continue digging barricade lines along the fire’s western edge.

Meanwhile, a human-caused fire in Summit County had not grown between Sunday and Monday, and was 35% contained at 1,460 acres by Monday night. As of Tuesday evening, it was 70% contained.

“Despite being challenged by steep, rugged terrain and dry fuel conditions crews are making great progress,” fire officials wrote.

Fire officials haven’t said exactly how people sparked the blaze between Echo and Henefer, east of Interstate 84. The fire isn’t threatening any buildings, but the Henefer-Echo Wildlife Management Area remains closed.