(CNN) -- Firefighters in northern Colorado faced another round of nightmare conditions Monday as high temperatures, low relative humidity and gusty winds whipped a blaze near Fort Collins.
Five residential subdivisions in the western suburbs of Fort Collins were under mandatory evacuation orders as of Monday morning.
More than 1,700 personnel were battling the blaze. Michael Stillman Maher, 30, was not one of them, although he allegedly wanted people to think he was, officials said. A fire chief reported seeing the Denver man driving a truck with a stolen government license plate and carrying phony firefighter credentials in the fire area Sunday night, officials said.
Maher was arrested in a Fort Collins bar early Monday morning and charged with impersonating a firefighter and theft.
The High Park Fire has consumed more than 58,000 acres so far, fire authorities said. It is about 45% contained.
"It just feels really dire. It's scary," resident Lupe Sandoval told CNN affiliate KUSA TV. "You feel bad for everybody."
The National Weather Service rates the fire risk in six Western states on Monday as "critical." Red flag warnings are posted across 10 states, noting high winds, low humidity and warm temperatures.
The High Park Fire, west of Fort Collins, has destroyed at least 181 homes, according to a statement posted on InciWeb, a U.S. multiagency fire response website.
"The assessment is still under way and this number will continue to grow," the statement said.
The blaze has moved through forests and neighborhoods, forcing thousands of evacuations and leaving a trail of destruction. It has claimed one life, a 62-year-old woman found dead in her burned home last week.
"It will be some time before this fire is out, but our challenge now is to make sure we do everything to contain the damage," said Agriculture Secretary Tom Vilsack, who oversees the Forest Service and toured the Colorado firefighting areas.
Colorado Gov. John Hickenlooper said a tree struck by lightning more than a week ago sparked the mammoth blaze.
Elsewhere in Colorado, firefighters are battling an 11,988-acre fire near Pagosa Springs that broke out last month. That blaze is 30% contained.
And a new fire broke out Sunday and quickly spread to 200 acres near Pueblo, forcing some evacuations of residents.
In New Mexico, the Whitewater Baldy complex has scorched more than 296,000 acres, the agriculture secretary said.
More than 3,200 fire personnel from across the United States are helping local departments battle the fire, which began on May 16. The blaze was 80% contained as of Sunday.