About 150 firefighters were assigned to the blaze overnight, as wind gusts as high as 70 mph were expected in the early morning hours, The Denver Post reported.
Firefighting helicopters and air tankers were grounded Sunday because of winds as ground crews worked to hem in the fire. Winds were clocked at 30-40 mph.
The firefighters were in home-protection mode, Sheriff Justin Smith said told residents of Marys Lake during a town meeting.
The Fern Lake fire started Oct. 9 by an illegal campfire in a remote area and has consumed 3,580 acres. As of Sunday evening, officials said, only one cabin had been lost and no firefighters had been injured.