Steamboat Springs Fire crews were working Tuesday to limit the spread of the Burn Ridge fire to the Mount Zirkel Wilderness Area about 16 miles north of Steamboat Springs.
The fire was first reported at 8 acres Monday afternoon but had grown to 35 acres by morning and nearly 50 acres by late afternoon Tuesday, Hahns Peak/Bears Ears District Ranger Kim Vogel said.
A pair of 20-person crews supported by a variety of aircraft were establishing a fire line along the existing Swamp Park Trail. The trail parallels the wilderness boundary about seven miles east of Clark.
"As it gets hotter and drier, with increased winds, our main challenge will be keeping it in the wilderness," Vogel said."
She explained the higher elevation of the wilderness increases the chances the fire will be stopped by natural boundaries boggy areas, rock cliffs and stands of aspen. Vogel said if the fire spreads west beyond the wilderness boundary into the remainder of the forest, the chances it will impact private land and property increase.
The fire broke out just outside the wilderness boundary Monday, the result of a holdover hot spot from a lightning strike last week, Fire Management Officer Kent Foster said.
The flames are consuming both pockets of blowdown timber and stands of living green trees.
Vogel said both the 20-member Craig Hotshots and the Yampa Valley Number Two team are working the fire line.
Foster said the crews on the ground are being augmented by a pair of helicopters. A Bell Ranger, known as a "type 3" chopper, is dropping water on the fire, as is a Super 205 "type two" helicopter. The latter is well-suited for high-elevation work.
Air tankers were also dropping retardant on the fire outside the wilderness boundary, and a single-engine plane was keeping an eye on things and coordinating traffic.
Vogel sad ground crews were moving in to solidify slurry lines established by the tankers.
"They have to make sure the fire is backed off of that line," she said. "You've got to follow it right up with the hand crews."
The spread of the fire on Tuesday was not so much a function of atmospherics wind and relative humidity but the dryness of the fuels, Vogel said.
Burn Ridge is in a relatively remote portion of the Medicine Bow-Routt National Forest that cannot be directly accessed by road. Because of its length, Swamp Park Trail is more likely to be used by riders on horseback than by hikers.
The landmarks closest to the fire in the Zirkel Wilderness include Wolverine Basin, about four miles east, and Dome Lake, also four miles east and about a mile south of Wolverine Basin.