More than 2,100 residents were being evacuated from the Air Force Academy's grounds Tuesday night as heavy smoke billowed from a wildfire that has burned an unknown number of homes near Colorado Springs.

The academy was telling families to leave two main housing areas, but an area of the 28-square-mile campus that houses cadets wasn't immediately evacuated. A new class of cadets is still scheduled to report on Thursday.

Fire officials had issued a pre-evacuation notice for the academy earlier Tuesday. El Paso County sheriff's officials have ordered an estimated 32,000 people to leave.

Fire information officer Greg Heule said earlier Tuesday that the fire was less than five miles from the southwest corner of the Air Force Academy's campus.

Television images showed homes burning and the Flying W Ranch southwest of the academy said on its website that the ranch had burned to the ground. Colorado Springs Fire Chief Richard Brown said "many, many homes" also have been saved.

Meanwhile, authorities in central Utah found one woman dead Tuesday when they returned to an evacuated area, marking the first casualty in a blaze that consumed at least two dozen homes and appears to be taking a turn for the worst.

Throughout the interior West, firefighters toiled in searing, record-setting heat that refused to relinquish its grip, as they struggled to contain blazes in Colorado, Utah and other Rocky Mountain states Tuesday.

Colorado has endured nearly a week of 100-plus-degree days and low humidity, sapping moisture from timber and grass, creating a devastating formula for volatile wildfires across the state and punishing conditions for firefighters.

"When it's that hot, it just dries the fuels even more. That can make the fuels explosive," said Steve Segin, a fire spokesman for the U.S. Forest Service.

All of Utah and much of Wyoming, Colorado and Montana were under a red flag warning, meaning conditions were hot, dry and ripe for fires.

Tuesday was the fifth consecutive day with temperatures of 100 degrees or higher in Denver, tying a record set in 2005 and 1989. On Monday, Denver set a record with 105 degrees. The previous record for June 25 was 100 degrees in 1991.

Other areas of the state also topped 100 degrees Tuesday, including the northeastern Colorado town of Wray, which hit 108, the National Weather Service said.

What the nation is now seeing is "a super-heated spike on top of a decades long warming trend," said Derek Arndt, head of climate monitoring at the National Climatic Data Center in Asheville, N.C.

The U.S. set 107 new temperature records Monday and in the past week has set 782 of them, which are large numbers but hard to put in context because the data center has only been tracking the number of daily records broken for little more than a year, Arndt said.

But what's truly impressive, Arndt said, is that in the past three days in Colorado and Kansas, nine sites have set records regardless of the date. Usually hottest-ever marks are set in the scorching months of July and August.

The scorching heat doesn't appear to be letting up soon. Segin said such prolonged heat is "extremely taxing" physically on firefighters, who are working long days and carrying heavy gear.

Television video from the 7-square-mile Waldo Canyon fire west of Colorado Springs, Colo., showed smoke and flames close to houses in a forested neighborhood northwest of Colorado Springs.

The fire was 5 percent contained.

Two specially equipped Air Force C-130 cargo planes were helping fight the fire, and a third was expected later in the day.

With the nation's privately owned fleet of heavy air tankers already in use or unavailable, U.S. Forest Chief Tom Tidwell said his agency had to call on the military to help.

Tidwell told The Associated Press in a phone interview Monday that about half of the nation's personnel who are usually assigned to large fires are working in Colorado right now.

"It's just because it's so dry," Tidwell said. "Not unlike New Mexico _ they saw very low snowpack, especially in that lower country. Hot, dry winds with dry fuels, you get the ignition, and this is what we see."

At the 136-square-mile High Park fire in northern Colorado, authorities increased the number of homes destroyed to 257, saying they found nine homes that hadn't been counted earlier. The total was already the highest of any wildfire in state history.

That fire was 55 percent contained.

In Utah, Sanpete County sheriff's officials haven't identified the body found or explained where the remains were found Tuesday morning while assessing damage in the area.

On Tuesday morning, officials announced that the 60-square-mile Wood Hollow Fire was 15 percent contained and lifted some evacuation orders amid predictions they'd contain the blaze even further. But winds fanned the flames again by afternoon, forcing authorities to shut down part of U.S. 89 near Indianola amid fears that the fire would jump the highway.

Evacuations were called for Fairview, a town of about 1,100 residents near the blaze, as the fire grew larger and more erratic.

Elsewhere in the West:

_ A fire that charred nearly 70 square miles west of Ruidoso, N.M., was 90 percent contained, with many residents allowed to return home.

_ A wildfire north of Helena, Mont., destroyed four homes and forced additional evacuations. Gov. Brian Schweitzer issued a state of emergency for four counties.

_ A wildfire in the Bridger-Teton National Forest grew from about 300 acres to 2,000 acres Tuesday, marking the first major wildfire of the season in western Wyoming.

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DeBruin reported from Indianola, Utah. Associated Press writers Susan Montoya Bryan in Albuquerque, N.M., and Rema Rahman in Denver; and AP Science Writer Seth Borenstein in Washington contributed to this report.