A portion of the 416 Fire.

Courtesy La Plata County on Facebook

Firefighters expect the 416 Fire burning in southwestern Colorado to reach homes soon, prompting the evacuation of more residents.

The fire is about 10 miles north of Durango has grown to 7.9 square miles as of Thursday. The new evacuees were warned in advance to leave Thursday morning.

According to InciWeb, the fire has moved southwest towards Hermosa Creek and has reached the Hermosa Campground, at the end of the 201 road. Fire managers say they expect the fire to reach the evacuees' homes within 12 to 36 hours.

Firefighters plan to use pre-positioned sprinkler systems, fire hoses and fire engines as well as aircraft to protect the homes. Firefighters have also scouted out places to build fire lines to limit the fire's growth.

About 1,500 residents in the area have already been evacuated because of the fire, which began June 1. It is burning in rough terrain and is 10 percent contained. Fire managers say the cause isn't known.

Now that the fire has grown in complexity, a Rocky Mountain Incident Management Type 1 Team will take over command of firefighting efforts on Saturday, June 9 with advanced abilities and resources to manage larger wildfires.

 The fire has shut down the historic Durango & Silverton Narrow Gauge Railroad, which runs through the area, at least through Sunday.