A 300-acre wildfire burning on Fort Carson grounds is about 50 percent contained.

The blaze is burning in grass and trees on the south part of the Army base. Authorities believe the fire was sparked by a lawn mower.

Fort Carson spokeswoman Brandy Gill says the Army base was notified of the blaze about 10 this morning. She says the fire is burning in grass and trees near the south part of the base. No structures are threatened.

Smoke from the fire briefly closed Colorado 115 this afternoon.

About 60 firefighters from Fort Carson and departments from Colorado Springs and El Paso County are fighting the blaze.