A wildfire that ignited on U.S. Forest Service land northeast of Silverthorne forced the evacuation of numerous residents in the Hamilton Creek neighborhood on the afternoon of Monday, Sept. 27.

The fire, which officials are calling the Ptarmigan Fire, was burning between 30 and 40 acres as of the latest update from the Forest Service on Monday night. No homes have burned.

The first reports of smoke sightings from Ptarmigan Mountain, just outside the border of the Ptarmigan Peak Wilderness Area, came in at around 4:30 p.m., according to Summit Fire & EMS Chief Travis Davis. At around 6 p.m., the Summit County Sheriff’s Office issued an evacuation order for residents on Lakeview Circle in the upper Hamilton Creek neighborhood, and a mandatory evacuation order was placed on the entire neighborhood at about 8 p.m.

As of 10 p.m. Monday, the evacuation orders were still in place along with pre-evacuation orders for residents in the Angler Mountain Ranch and South Forty neighborhoods. Summit County Sheriff Jaime FitzSimons said there were about 290 homes in the Hamilton Creek neighborhood.

The initial firefighting response Monday was conducted entirely by aircraft because fire conditions were deemed too dangerous to send in ground crews. Chris Stewart, deputy district ranger with the Dillon Ranger District, said two small air tankers, a large air tanker and a helicopter dropped water and slurry around the site Monday afternoon in an attempt to stymie the fire’s growth and prevent it from moving downhill toward residential areas.

Firefighters remained in the area overnight to monitor the blaze and to try to determine the best areas of attack for ground crews set to arrive Tuesday morning.

The fire is burning in heavy mixed timber, including stands of dead and downed lodgepole pine trees. Davis said he didn’t expect the fire to grow much overnight, and he said the fuel conditions in the area were heavily influencing its behavior.

“What’s happening up there now is what we call a dirty burn,” Davis said. “So what the fire is doing is it’s skulking around on the ground. It’s not very big until it finds this jackpot of dead trees, and then it just takes off. So I can promise you — I don’t want to minimize it, this is the business we’re in, and we see these things — but it looks worse than what it truly is at this point. …

“It doesn’t have that big, flaming wall that you see on a lot of big fires, and so it’s not throwing huge embers out front and starting spot fires. It really is just skulking around until it finds something dry enough that can burn, it shoots up into the air, we see a little black smoke, and then it just kind of lays back down. Because we don’t have the right conditions — the high heat, the low humidity, the winds — what it’s doing right now is pretty much what you’re going to see. I don’t really think we’re going to see much growth.”

Fire activity is expected to pick back up Tuesday, and officials said ground crews and significant air support would be on scene working to contain it. There is some hope that weather conditions over the coming days could help out, as well.

“The fire should change here with the temperatures dropping,” FitzSimons said. “As we all know, it’s been getting below freezing at night. It’s been getting really cold, and we’re expecting weather to move in over the next few days. So that’s all good news.”

The National Weather Service forecast a high of 68 degrees Tuesday with a strong chance of precipitation by Tuesday night. Wednesday should bring more rain and possibly some snow to the area.

While there is some good news, many residents were left contemplating the worst Monday night.

“I was looking, I think, at about like 7:45,” Hamilton Creek resident Michelle Kirk said. “I was keeping up to date on the news, and then we started packing up the car, and we went out, and I could see flames up on the hill. … I hope we have a house tomorrow.”

The American Red Cross has an evacuation shelter set up at Summit Middle School in Frisco. Both Summit Middle School and Silverthorne Elementary School are expected to operate normally Tuesday.

The Summit County Animal Shelter will be open at 9 a.m. Tuesday to provide support for evacuees with pets.

Recreational access to the North Park Pond as well as Ptarmigan and Angler Mountain trails have been closed. Dillon Dam Road has also been closed until further notice, and Summit County Commissioner Elisabeth Lawrence said there could be traffic impacts Tuesday. She asked community members to be respectful of firefighting operations.

“You could see road closures and delays in various areas,” Lawrence said. “That is all set up to fight the fire. … So let’s do what we can to stay out of folks’ way and make sure that people and helicopters can get across the road and do what they need to do.”

Editor’s note: Lindsey Toomer and Nicole Miller contributed to reporting on this story.