Fire managers said the 416 Fire could reach homes by Friday night in the Hermosa area, where an additional 500 homes were evacuated Thursday morning and another 750 homes were placed on pre-evacuation notice.
The evacuations were ordered for two reasons: to protect the public and to clear the area for firefighters to work, said Vickie Russo, a spokeswoman for the Type II team managing the blaze.
"We're trying to be proactive instead of reactive," she said, "and we'd rather folks be out of harm's way as well as be out of the way of any firefighters that need to get in there and engage the fire."
It's not guaranteed fire will reach residences, but "it's possible," Russo said Thursday night.
"A great deal of preparation and hard work has gone into structure protection in the Hermosa area," according to a news release issued Thursday by the Type II command team. "Firefighters will defend homes by using tactics such as prepositioned sprinkler systems, hose lays, engines, hand crews, backfiring and air support from helicopters and fixed-wing aircraft. Resources will be spread throughout the area and prepared to implement these structure-protection strategies as the fire progresses toward homes."
The 6-day-old fire started about 10 a.m. Friday and had grown to 5,103 acres as of Thursday morning, the most recent estimate available. It was only 10 percent contained.
In total, more than 1,000 homes are evacuated and more than 1,500 homes are on pre-evacuation, according to La Plata County.
U.S. Highway 550 is expected to be open from 8 a.m. to 6 p.m. Friday for limited through traffic, meaning drivers can move through the corridor, but they aren't allowed to stop or drive down side roads. They will be escorted by law enforcement. Otherwise, the highway remains closed between mile markers 32 and 44, according to the Colorado Department of Transportation.
A Type I team will take command of firefighting efforts at 6 a.m. Saturday. They arrived for a briefing Thursday evening, and will spend a majority of the day Friday "shadowing" the Type II team to learn more about the team's firefighting efforts.
The Type I team brings similar skills as the Type II team, but with advanced qualifications to manage larger, more complex fires.
The La Plata County Sheriff's Office spent a majority of Thursday morning in the Hermosa area, going door to door to inform residents they should be prepared to leave.
The Type II team used burnouts on the southwestern side of the fire in an effort to prevent the fire from reaching structures in the area.
Air tankers used slurry for the first time in several days.
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Crews spent Wednesday and Thursday protecting structures in the Hermosa area and building defensible lines along the Highway 550 corridor.
"Crews are helping residents remove flammable material from around their homes and helping create sensible space around residences to get ahead of the fire's movement," said Bethany Urban, a spokeswoman for the Type II firefighting team. "We're really trying to get ahead and prepare those areas so that they can scout ahead of the fire and identify locations that they can engage the fire, so if it does start to spread they can engage it in an area that is safe to do so."
Six helicopters are available to fight the fire, but they will be used only if it is necessary to aid the overall firefighting strategy, she said.
"We're using those as conditions warrant," Urban said. "It kind of depends on the conditions of the weather as well as what they're trying to drop on, what kind of trees, what type of ground cover, and given that the topography is so complex, there are some areas where it's effective to drop suppressants from the choppers and others where it's not really very effective."
Firefighters will continue to battle against unfavorable weather conditions, with temperatures forecast in the mid to upper 80s this weekend.
The federal incident command team had more than 600 firefighters battling the blaze.
Durango and Pine River Valley residents woke up to a heavy dose of smoke Wednesday morning, and smoky conditions are expected to continue
"As the fire continues to grow, air quality could become an issue," Urban said. "There may be some decreasing air quality in the area."
San Juan Basin Public Health advises that if visibility is less than five miles, smoke has reached levels that are unhealthy.
"Consider limiting outdoor activity when moderate to heavy smoke is present," the health agency said in a press release.
Because of the area's extreme drought, almost everywhere in La Plata County is under type II fire restrictions, which ban all open flames and smoking outside of homes or vehicles.
To receive emergency notifications from La Plata County, including evacuation and pre-evacuation notices, residents can dign up at bit.ly/CodeRed_signup. The notices will come via text messages or email. A Type I federal firefighting team is mobilizing to take command of the 416 Fire north of Hermosa on Saturday.
"The big distinction between Type I and Type II is going to be complexity of the fire," said Steven Hall, a spokesman for the Rocky Mountain Area Coordination Center. "Complexity that typically makes us look at a Type I team versus a Type II team is threats to homes and private property. That's going to be one of the big deciding factors."
Evacuations and pre-evacuations were extended on Thursday to more homes in the area, including some in Hermosa.
High temperatures combined with low humidity helped the 416 Fire to grow to more than 5,100 acres as of Thursday. Containment remains at 10 percent.
The fire started on Friday, June 1 and rapidly grew to more than 1,000 acres by June 2.
