STEAMBOAT SPRINGS — Aerial mapping conducted Monday evening showed the Middle Fork Fire burning north of Steamboat Springs had grown from its original 15 to more than 3,500, according to fire officials.

The fire had grown to 137 acres overnight Sunday, according to Aaron Voos, public affairs specialist for the U.S. Forest Service covering Routt National Forest. City of Steamboat Springs officials had estimated the spread had reached 500 to 700 acres by Monday evening but the fire was later confirmed by aerial mapping to be 3,522 acres.

Voos said that while the fire is expanding, it’s not going to spread by miles at this point. He said it’s also mainly spreading east, toward a small system of lakes, and that no evacuations or closures have been put in place.

The fire was initially reported as spanning about 15 acres Sunday, according to David “Mo” DeMorat, Routt County’s emergency operations director. The Middle Fork Fire, as it has since been named, is currently burning in the Zirkel Wilderness Area west of Lake Margaret between the Middle and North forks of Mad Creek. It’s about 10 miles north of Steamboat, and smoke is visible from the area.

The fire had been burning south of the Luna Lake Trail, according to Sean Carey, assistant fire management officer for Routt National Forest.

It then reached Luna Lake by the evening and headed toward Mount Ethel. The blaze is currently within one mile of the Continental Divide Trail and has burned over Luna Lake and Fish Hawk trails.

Carey said Monday there are structures to the west of the fire, located on private land, but no structures in the fire’s immediate vicinity. The blaze is moving mainly east and slightly north.

Five ground crews were on scene initially but left the scene late Monday afternoon. Current efforts to battle the blaze are being conducted with three Type-1 helicopters.

No mutual aid has been requested so far from local fire protection districts, Carey said, but they are being kept informed in case they need to be called upon.

While weather forecasts call for an incoming cold front that could bring several inches of snow to the area, Carey said it wouldn’t do much to extinguish the fire.

The #MiddleForkFire_CO, #Routt NF is growing this afternoon. No acreage update yet, but please do not head into the fire area. Photos, hunting, etc… Bad ideas pic.twitter.com/IHPA1MUzXj

— Medicine Bow-Routt NFs & Thunder Basin NG (@FS_MBRTB) September 7, 2020

“It’ll help,” he said. “I don’t foresee it putting the fire out though.”

Voos said the fire could again grow ahead of the cold front’s arrival.

“When we first heard of it, it was a couple acres then grew to 137 acres,” Voos said. “(It has) the potential to do the exact same thing today.”

He said winds accompanying the cold front could potentially help grow the blaze.

Once a fire reaches this size, Voos explained, especially in an area where there are rocks, “the fire may die down a bit with moisture and colder temperatures but then carry over and come back to life in the next warming trend.”

Warm temperatures are expected to return after the cold front leaves the area Wednesday or Thursday.

While there are no trail or road closures as of now, Voos recommends people avoid the area of the fire and the nearby trails in the Zirkel Wilderness, especially on the Luna Lake and Fish Hawk trails. Though with the incoming weather, it’s likely most people will be exiting the forest, he said.

The cause of the fire, which is currently at zero containment, is attributed to lightning, according to Carey.

To reach Bryce Martin, call 970-871-4206 or email bmartin@SteamboatPilot.com.