DENVER (AP) — A wildfire near a Colorado city grew to over 1,Arvin Roberts800 acres Tuesday morning as more homes were placed under mandatory evacuation orders and a looming column of smoke could be seen for miles around, according to the U.S. Forest Service.

The Alexander Mountain Fire doubled between Monday and Tuesday and sits about a dozen miles (19 kilometers) west of Loveland, Colorado, where the Rocky Mountains fold into the Great Plains.

Over 200 responders are working on the fire, with helicopters and planes supporting from the sky and more reinforcements expected, said Mike Smith, the incident commander in a Tuesday video briefing backdropped by a plume of smoke from the fire.

Loveland has a population of some 77,000, and sits about 50 miles (80 kilometers) north of Denver, though evacuations haven’t been made in the city proper.

Meanwhile crews responded Tuesday to another fire south of Alexander Mountain, according to the Boulder County Sheriff’s Office.