Controlled back-burns conducted Monday helped slowdown the 416 Fire, which was last reported at 23,378 acres and 15 percent contained.

Burnout operations occurred well into Tuesday morning, Knight said. Crews used numerous back-burns near the Falls Creek subdivision to help firefighters in areas where they couldn’t directly engage the flame. These efforts created a large plume of smoke as stronger fuels are burned.

“They were using fire in places where the terrain makes it difficult to make a direct attack,” said spokeswoman Jamie Knight. “A lot of what was seen yesterday (Monday) was successful tactics to use fire to help remove fuels in a manner that those firefighters could control.”

Though the fire has gotten close to several residences, no structures have been damaged. The mitigation techniques that both firefighters and residences did in preparation of the fire helped prevent any structures from being lost.

“That’s a huge win for the firefighters and the residences there,” Knight. “It’s becoming more evident over the last few days that the work residences did before the fire really aided firefighters working to protect structures.”

Crews plan to spend Tuesday using more back-burns in an effort to secure lines that are already being created and building more lines in preparation of the fire spreading. Similar efforts will be utilized on the northern perimeter. A control line around Purgatory is complete in the event the fire travels that far north.

“A lot of work goes into making sure the lines are strong and are going to hold when we are ready to use them,” Knight said. “We’ll be making sure that lines are in and ready to be used if we should need them.”

Crews continue to patrol the eastern perimeter of the fire to maintain control lines along the U.S. Highway 550 corridor.

“There’s parts that are fairly secure at this point,” Knight said. “They’re still doing a lot of work making sure there’s no heat anywhere near the control line.”

Over 900 firefighters are working on the fire. They will be aided by eight helicopters dropping buckets of water on hot spots Tuesday. The air tanker base in Durango does have air resources available should officials need them, but air tankers haven’t been as effective as helicopters because of the terrain, Knight said.

“They’re certainly a resource there that we can use and will use if the situation dictates,” Knight said, “but there’s no definitive plan that they will be flying at this time of day.”

Temperatures are expected to be in the low 80s, with a relative humidity between six and 12 percent, Knight said. Wind gusts up to 20 mph are expected in the afternoon, which officials predict will lead to extremely active fire behavior.

“Unfortunately, we’re expecting a similar pattern to what we saw yesterday,” Knight said.

The U.S. Forest Service announced Sunday it intends to close the San Juan National Forest. The closure is expected to take effect Tuesday. Also on Tuesday, La Plata County government plans to enact Stage 3 fire restrictions, and the city of Durango will consider closing trails and open spaces in city limits, including Animas City Mountain, Carbon Junction, Dalla Mountain Park, Horse Gulch and Overend Mountain Park.

The Durango & Silverton Narrow Gauge Railroad extended cancellations of all service until at least June 30. Passengers will receive an automatic refund. The railroad said in a news release that it plans to offer limited service using a diesel locomotive but has not released a time line for doing so.

Highway 550 will continue to be closed Tuesday to aid firefighting efforts. The road will be closed from mile marker 32 to 64, which is from Cometti/Mead Lane to the top of Molas Pass. The Colorado Department of Transportation urged drivers not to be a “lookie-loo” and to stay clear of the southern closure point.

The Burro fire, roughly 10 miles west of the 416 Fire, has reached 2,684 acres and has no containment. The Type I team has assigned 168 fire personnel to battle that fire.

asemadeni@durangoherald.com