OREM — The wildfire that ignited on Mount Timpanogos Saturday, burning thousands of acres and forcing evacuations, started at a police gun range, according to Utah Fire Info.

Investigators have determined that the fire was caused by target shooting at the Orem Police Gun Range.

A statement from Orem officials said the officer at the scene when the blaze began is cooperating with investigators.

“In addition to the state’s review of this case, the city of Orem is currently conducting an internal review and safety audit into the matter as well,” the city statement says. “This information will be released as soon as it is completed.”

The fire was an estimated 3,450 acres Monday morning and was 10% contained, according to Spencer Cannon, public information officer for the Utah County Sheriff’s Office.

About 15 homes within and at the mouth of Provo Canyon were under “direct threat” from the fire and were evacuated Saturday afternoon.

Occupants were allowed to return to their homes the following morning.

U.S. 189 through the canyon had been closed until reopening early Monday.