The Fern Lake fire, burning in Rocky Mountain National Park since Oct. 9, more than doubled in size overnight Friday, forcing the evacuation of 583 homes early Saturday.

The 3,584-acre fire, sparked by an illegal campfire in the park, exploded early Saturday when it was pushed by strong winds, with gusts up to 75 mph.

“The wind last night was very strong and fanned the flames,” said John Schulz, spokesman for the Larimer County Sheriff’s Department. “It jumped the lines.”

An unoccupied, privately owned cabin was destroyed, and many others were threatened, Schulz said.

Fire spokeswoman Traci Weaver said teams made good progress fighting the fire Saturday, but high winds were expected again Sunday, especially late in the day.

A Type I incident-management team will assume control of the fire Sunday.

“What we really need is snow,” Weaver said.

Snow, however, is not in the forecast. A cold front Sunday was expected to bring more gusts but not much moisture.

As the fire raced through Moraine Park overnight Friday, it covered 3 miles in 35 minutes, Weaver said.

“The fire was spotting a mile ahead of itself, which is an incredibly long distance,” she said. “What happened last night was a rather unexpected wind event.

“That is way beyond any of our predictive tools to say what a fire would do. It just moved incredibly fast.”

Weaver stressed that only patches of the park had been affected as the fire leapt forward.

“It’s not a moonscape out there,” she said.

Before Friday night, the fire had been listed as 1,515 acres in steep, rough terrain. Containment had been up to 40 percent. Weaver said she could not estimate the level of containment Saturday.

For most of November, the fire smoldered quietly, being monitored by about a dozen firefighters, with containment expected by Dec. 17. Suppressing the fire on the ground was considered extremely unsafe because of the terrain, and officials expected the fire to diminish once the snows came.

An evacuation center has been set up at Estes Park High School. The Salvation Army and Red Cross are providing meals for the evacuees.

Large animals were being taken to the Stanley Park Fairgrounds, 1209 Manford Ave.

Lori Ellis, a 21-year resident of Estes Park, lives on Eagle Cliff Road near Colorado 66. She, her husband, Sam, and her 13-year-old-son, Dante, sat around a table in a nearly empty lobby at the high school Saturday after being evacuated at 6 a.m.

“We knew the smoke was pretty potent,” Ellis said.

Realizing that the smoke was noticeably worse and infiltrating their home, they raced to get out, searching only for cellphones and a cat carrier. They were gone within minutes.

“I’ve never seen a year like this,” she said, noting that there hasn’t been a substantial snowfall in the area this season. “It’s been severe.”

Kay Rusk, who has lived in Estes Park for 20 years, is a former smoke jumper. She said she awoke to the smell of smoke at about 3:30 a.m. and was not surprised when she received a warning call at about 7 a.m.

“We were just kind of waiting,” she said. “The moon was red.”

Helicopter and tanker assistance for the wildfire has been grounded because of high winds and poor visibility, according to Rocky Mountain National Park spokeswoman Kyle Patterson.

Support to fight the fire increased from 61 firefighters Friday to 200 Saturday. Two hot-shot crews were on their way to the wildfire, and numerous local fire engines were headed to the area, officials said.

The arrival of two heavy air tankers from Southern California was delayed at least one day because of poor visibility in the area, Patterson said.

Temperatures were about 20 degrees above normal in Estes Park on Saturday, with a high around 60degrees. Jim Kalina, meteorologist for the National Weather Service in Boulder, said winds will gust to around 30 mph Sunday.

A park ranger said there hasn’t been a wildfire in the Fern Lake area in a thousand years.

Weaver said the wildfire spread through timber pockets and got into the upper canopy of some trees, but firefighters were able to “knock it down” from the trees, Weaver said.

The evacuation of Moraine Park Campground was ordered at 1:50 a.m. Saturday, Weaver said. Warnings were sent to about 1,100 home phones and cellphones.

Seven campers were notified in person early Saturday, Weaver said.

The Larimer County Sheriff’s Office ordered evacuations for Colorado 66 and all adjacent streets, and Marys Lake Road up to Moraine Avenue to Marys Lake on the west side. Residents of High Drive and adjacent streets were allowed to return home by showing proper identification, but that area remains on pre-evacuation alert.

Residents evacuated from the west side of Marys Lake Road and adjacent streets were permitted to return home, and that area remained on a pre-evacuation notice; however, access to the neighborhood was unrestricted.

The east side of Rocky Mountain National Park remained closed.

Jason Pohl: 303-954-1729, jpohl@denverpost.com or twitter.com/pohl_jason

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