CHEYENNE, Wyo. (AP) — Officials say a Colorado National Guard engineer unit training with explosives started a wildfire that has burned about 22 square miles in southeast Wyoming.

The Sawmill Fire began last Saturday on the Wyoming National Guard’s Camp Guernsey training area. No structures were lost and no one was hurt, but the fire forced the state to evacuate and close the east side of nearby Glendo State Park.

The fire is 60 percent contained, and the entire park reopened Thursday.

Wyoming Guard spokeswoman Deidre Forster says the incident remains under investigation.

The training area is about 100 miles north of Cheyenne. Besides the Wyoming Guard, it has been used by the U.S. military as well as various state, federal and local government agencies that need weapons and explosives training.

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