Find the latest on this fire | Live updates: 3 wildfires burning in the foothills north and west of Denver
A wildfire burning in northern Colorado has prompted mandatory evacuations Monday afternoon in Larimer County.
Crews are responding to Alexander Mountain fire near Sylvan Dale Guest Ranch and U.S. 34, west of Loveland, Larimer County Sheriff’s Office said in a social media post about 11:45 a.m.
In an update Monday evening at 7:45 p.m., aerial crews with the U.S. Forest Service estimated the fire had grown to 950 acres and zero containment.
Firefighters from several agencies were en route and on scene to fight the fire from the ground and sky, including pilots trained to operate the state’s new Firehawk, a military helicopter modified to fight fires, according to a spokesperson with the state’s fire division, Tracy LeClair.
The state also sent two single engine air tankers, a multi-mission aircraft, and a Tanker 10, which can drop 9,400 gallons of fire retardant within 8 seconds across an area up to a mile long. Horsetooth Reservoir is being used as part of the fight, and boaters and others are asked to avoid the area, according to the Larimer Department of Natural Resources.
U.S. 34 is shut down between County Road 29 and County Road 43 through Big Thompson Canyon as firefighters tried to extinguish the fire, the sheriff’s office said.
Mandatory evacuations were ordered for people living in the following areas:
- U.S. 34 from the town of Drake to The Dam Store, a gift shop near the mouth of the Big Thompson Canyon west of Loveland, as well as those near Storm and Palisade mountains
- The area of Waltonia Road, Eden Valley to Sunriser Ranch, and Sylvan Dale to Ellis Ranch
- County Road 18E from Pole Hill to Pinewood reservoir, which is northwest of Carter Lake
Voluntary evacuations have been issued for people living off County Road 86C, north of Rustic, residents living off Glade Road from Highway 34 to Indian Creek, and those living off County Road 18E from County Road 31 to County Road 29.
“Gather essential items and prepare for evacuation,” officials wrote in an alert at 12:53 p.m.
Evacuation centers are set up at Namaqua Elementary School in Loveland, at 209 N. Namaqua Ave., and at the Estes Park Events Complex in Estes Park at 1125 Rooftop Way. Residents can bring their large animals to The Ranch at 5280 Arena Circle.
Firefighters are battling against conditions that allow fires to easily and quickly spread. Officials have not yet announced a possible cause for the Alexander Mountain fire.
Temperatures at the mouth of the canyon were in the mid-90s Monday afternoon and very low relative humidity levels were recorded at about 10%, Paul Schlatter, a meteorologist with the National Weather Service’s Office in Boulder, said.
Thankfully, winds were relatively low, clocking in between 8 to 15 mph, he said.
“That could be a lot worse,” Schlatter said. “Stronger winds would spread the fire a lot quicker, but 8-15 mph is on the manageable side of things.”
Typically at night, relative humidity levels rise and temperatures drop — an equation that often helps firefighters control flames. Tonight’s forecast shows relative humidity rising to only 25%, Schlatter said, “which is still exceptionally dry for relative humidity overnight.”
Winds overnight are forecast at 6 to 10 mph, he said.
The hottest part of the fire has been in a forested area on the north side, on Alexander Mountain, which rises from the Big Thompson Canyon, north of U.S. 34. The mountain rises 1,500 feet “straight up” off the highway, before it flattens out on top and becomes less rugged, Schlatter said.
“Once the fire gets up in that area, it may not spread as fast especially if the winds stay the way they are because the terrain is a little more flat,” he said. “In the canyon itself, that’s why the fire spread so fast, because it is steep and rugged.”
Thick smoke from the fire could be seen for miles as the fire moved north, the Boulder County Sheriff’s Office said about 12:30 p.m. Boulder County officials urged residents not to call 911.
An air quality health advisory was issued Monday urging people in southeastern Larimer County to limit time outside if the smoke became too thick. Those with heart disease, respiratory illnesses, young children or older adults could be more at risk, the Colorado Department of Health and Environment said Monday.
“If visibility is less than 5 miles in your neighborhood, smoke has reached levels that are unhealthy,” the alert said.