The Lightner Creek Fire grew to approximately 300 acres on Thursday, fueled by dry conditions and gusting winds.
There is zero containment of the fire, which grew to about 300 acres by Thursday afternoon.
"It is hard to establish containment in this terrain," said Scot Davis, public information officer for the Durango Interagency Command.
Bulldozers and more air tankers are being called to the fire, Davis said. Air tankers are coming from Denver and bulldozers from around Durango will be used to build more fire breaks.
Firefighters are putting in two fire breaks, to the south of the two fires, he said.
A Type II Incident Management Team will take over fire management on Friday morning, he said. The classification of management team is based on the terrain and a fire's proximity to structures. A Type I team handles the most complex fires.
More resources and more money will be available when the Type II team takes over, he said.
A Type III management team hwas handling the fire on Wednesday and Thursday.
The state's multimission aircraft was flying over the Lightner Creek Fire midday Thursday to map it and determine the exact acreage, said Caley Fisher, of the Colorado Division of Fire Prevention and Control.
The La Plata County Fairgrounds was declared the command center for a Type II incident team, which will bring more equipment and crews.
The evacuation center at the fairgrounds was relocated to Escalante Middle School, and public transportation was provided for those who needed help moving. Pets are not allowed at Escalante, but they can be taken to the La Plata County Humane Society.
Meanwhile, haze from the fire was drifting across the region.
"The smoke will likely drift south toward Durango and Pagosa Springs today," said Matthew Aleksa, a meteorologist with the weather service. There looks like there is smoke in the Animas Valley extending to Pagosa right now,"
The fire was declared a disaster emergency by Gov. John Hickenlooper. The governor's declaration includes authorization for the Colorado National Guard to provide support if requested.
Aerial firefighting operations were interrupted for up to an hour Wednesday evening and two aircraft had to jettison fire retardant uselessly after at least one drone was reported in the area,
Air operations were grounded around sunset because drones made it unsafe for pilots to fly, said Chris Tipton, fire management officer for the U.S. Forest Service. Flying drones in a fire operations area is a federal crime.
Pilots can't see drones and they can get into a plane's engine or go through the windshield and harm the pilot, he said.
The planes were ready to drop retardant on the section of the fire moving toward Durango when they had to be grounded, he said.
But instead, two planes had to jettison about 1,600 gallons of retardant worth between $8,000 and $10,000. One plane dropped it too high above the fire to do any good and another plane dropped it near the airport, he said.
The Durango Police Department spoke with two people flying drones over the fire Wednesday night, La Plata County spokeswoman Megan Graham said.
Evan Niccum was flying a drone in the Rockridge area and a boy under 18 was flying a second drone; others also were reported in the area, she said.
The police turned the information about the pilots over to the U.S. Forest Service, she said.
Planes started dropping retardant on the fire around 8 a.m. Thursday morning and planned to fly all day, Tipton said. There are five single engine air tankers, two large air tankers, one aerial supervision module, one air attack airplane and one helicopter.
A red flag warning was in effect until 8 p.m. Thursday for most of western Colorado and eastern Utah, including the Durango area. The National Weather Service predicted winds of 10 to 20 mph, with gusts up to 35 mph in the afternoon.
The fire was reported about 4 p.m. Wednesday in the 1200 block of Lightner Creek Road, and quickly consumed 50 acres on the west side of the canyon a couple miles west of Durango. It is believed to have started at a house at 1255 Lightner Creek Road. Durango Fire Protection District, La Plata County Emergency Management, Los Pinos, Upper Pine, Southern Ute Agency Fire Management, Ute Mountain Ute Agency, U.S. Forest Service, Bureau of Land Management and Colorado Division of Fire Prevention and Control are all helping to fight the fire, he said.
Staff writers Mary Shinn, Jonathan Romeo, Mia Rupani and Alex Semadeni contributed to this report.