Officials planned to continue using what they say has been a successful strategy and said that progress made over the next day or so will be key in determining when residents will be allowed to return to their homes, beyond the eastern edge of the fire.
"We feel pretty confident with what we've done," said Joe Stam, who is leading the team of firefighters. He addressed dozens of residents at a community meeting late Wednesday.
Firefighters set their own fires, called "burnouts" or "backfires," Tuesday to create a line meant to block the fire and draw it away from park headquarters near West Glacier.
Fire officials said a successful burnout near West Glacier likely added about 2,500 acres to the size of the fire, which was estimated at 14,500 acres before officials could conduct an aerial survey. Spokesman Pete Buist said there was still concern about the eastern edge of the fire and that further burnouts were planned.
"We feel a lot better after yesterday and today's burnouts, than we did two days ago," Buist said Wednesday, adding that fire officials do not yet consider the area safe from the advancing fire.
The fire remained west of West Glacier, which has about 250 year-round residents and about 400 residents during the summer. About 500 residents of the town and the forested area along the edge of the park are out of their homes.
Burnouts are a common tactic used in wildland firefighting. Fire officials say the main fire creates a draft as it consumes oxygen, and that draws the backfire toward it. This was visible Wednesday from the West Glacier golf course, where some people gathered to watch the plumes of smoke on the nearby mountain. When the two fires meet, they have no more fuel to burn.
The fire is one of three major fires burning partly or wholly in the park. They total more than 50,000 acres and are being battled by more than 2,000 firefighters.
A second fire in extreme northwestern Montana and just six miles from the Canadian border has charred 21,374 acres and has also burned into the western edge of the park from the Flathead National Forest. It has destroyed six homes and 19 outbuildings and is still threatening about 100 homes and cabins near the North Fork of the Flathead River.
The third fire has burned about 18,600 acres on Flattop Mountain. The fire is now threatening some historic buildings, including the Granite Park Chalet.
The blaze that shut down Mesa Verde National Park was completely surrounded by fire lines Thursday after fire crews got some cooperation from the weather.
Low winds and high humidity were seen across Colorado on Wednesday, signs that herald the arrival of the annual monsoon season.
The number of firefighters at the 2,750-acre Mesa Verde fire has been trimmed from 72 to 40, said Mark Amann, spokesman at the federal Rocky Mountain Area Coordination Center in Denver.
Southeast of Meeker, Colorado, fire crews said a 600-acre fire that threatened more than a dozen homes was 70 percent contained and was expected to be fully contained Friday.
Firefighters in Washington state, meanwhile, paused to remember a fallen comrade Wednesday, then battled scorching heat and conditions so dry that any spark could instantly start a new wildfire.
A memorial service was conducted at a fire camp for helicopter pilot Randall Harmon, of Grants Pass, Ore., who died in a crash Friday while dropping water on a fire on the Colville Indian Reservation.
The fire in the Pasayten Wilderness of north-central Washington grew about 2,000 acres on Wednesday to 71,570 acres, and was being fought by more than 1,000 firefighters.