CANON CITY, Colo. - Authorities say the Eightmile Fire has burned 700 acres about 6 miles north of Cañon City.
The fire began on Monday afternoon after a thunderstorm moved through the area.
The fire activity overnight remained at moderate intensity with fire backing downslope and torching trees, said fire information officer Gregg Goodland.
But the wildfire gained strength on Friday and smoke was visible 45 miles away in Fountain.
The fire is not threatening any structures.
It is burning toward the northeast in very rugged, mountainous terrain covered with Ponderosa pine, oak and juniper, officials said.
Phantom Canyon road is closed between mile markers 8 and 12.
There are currently 35 firefighters working the fire. Four 20-person hotshot crews have been ordered.
Air support includes a heavy helicopter and two single-engine air tankers. Officials have ordered two heavy air tankers, but it's not known when they will arrive.