Authorities ordered mandatory evacuations Thursday of dozens of homes close to a wildfire blazing near a scenic canyon in northern Colorado, even going door to door to warn residents of impending danger.
Residents of 80 homes in the area a short drive from Fort Collins had been instructed previously to be ready to leave on short notice, said U.S. Forest Service spokeswoman Kristy Wumkes.
The fire has grown from 1.5 square miles to 8 square miles since Wednesday as erratic wind gusts kicked up by dry thunderstorms swept through the region at up to 50 mph.
About 400 firefighters are working to contain the blaze. Their efforts are being supported by a heavy air tanker and helicopters that together are capable of dropping thousands of gallons of fire retardant and water on the flames.
Officials think human activity started the blaze, which was first reported Monday, but are still investigating.
The growing northern Colorado fire was one of several burning in the West on Thursday.
A fire in northern Arizona grew to more than 10 square miles and led to the evacuation of a historic mining town.
Forest Service spokeswoman Michelle Fidler said gusts of up to 40 mph are expected in the Prescott National Forest, near the mountain community of Crown King, about 85 miles north of Phoenix. Most of its 350 residents had already evacuated.
Fidler said that as wind pushed the fire north, crews focused on slowing the blaze from the west, where communication towers are threatened.
The fire prompted an evacuation order Sunday and has destroyed three homes and a trailer. The blaze started at a home, but investigators are still working to determine the cause.
Other fires dotted the state but did not threaten any structures, authorities said.
Meanwhile, separate blazes in northern and southern New Mexico have cast a haze of smoke over the state but have not caused property damage or prompted evacuations, authorities say.
The Colorado fire 20 miles northwest of Fort Collins is scorching a drought-stricken area of steep, rocky terrain dotted by dry ponderosa pine trees, grass and shrubs. The region north of the Cache La Poudre River is popular with hikers and rock climbers.
A thick smoky cloud over Fort Collins prompting health officials to warn that children and people with lung or heart problems should stay indoors.
The haze extended 65 miles south to Denver prompting concerns that it would affect planes at Denver International Airport, but officials there said operations had not been affected.
A human-caused fire near Fort Collins in April 2011 scorched 5 square miles, destroyed 13 homes and temporarily displaced residents from 335 homes.
Though the evacuation is mandatory, officials are not authorized to forcibly remove anyone from their homes.
Area resident John Hasler said he's not leaving.
"We're not going to have a fire come down and burn our house," Hasler said, adding that his home is surrounded by a lawn of closely cropped grass. "If does, it'll burn grass and it wouldn't be big flames. I'm really confident that I can handle it with my garden hose."
Hasler said "it's a totally different situation" from the late March wildfire that killed three people south of Denver.
This blaze is the first wildfire to prompt evacuations in the state since those deaths.
"If my home was in the timber, I'd be really worried."