The wildfires that have been racing through western and southern Utah this summer are fought with more than the bravery of smoke jumpers and the muscles of crews wielding shovels. Another huge component is brains.

The applied science of fighting fires occupied many of the experts last week at a staging area in Dugway Proving Ground, the Utah National Guard's Bullene Barracks. Able to house 640 soldiers, the buildings were the nerve center of the battle against the range fires that roared out of control for several days.From the Topliff fire near the junction of Juab, Utah and Tooele counties, to the fire called White Rocks, northwest of Dugway Proving Ground, the 15 blazes consumed 17,280 acres of sagebrush, cheatgrass and pinyon-pine. Most were started by lightning, but a few were the result of carelessness.

By Thursday, almost all were extinguished - beaten by tenacity, cooling weather and one fortuitous shower drenching a pinyon-juniper forest that would have been hard to mop up otherwise. Six or eight fire engines were parked at the barracks. Out in the desert, only a few 20-person crews remained to shovel through hot spots or patrol by helicopter, searching for flare-ups.

Within the cinder-block headquarters, managers - some still dressed in fire-grimed work clothes - had time to handle more mundane chores. They used laptop computers to write fire narratives, or checked the global positioning satellite network to calculate the exact coordinates of fires, or handled the paperwork needed to demobilize scores of firefighters.

They had time to pause and think back over the fight they were finishing. For a while, fire had the upper hand.

Topliff blew up two days before, said Kirk Gardner, a wildlife biologist for the Bureau of Land Management's Salt Lake District and a resources advisor on the fires. "One of the engine crews over at the Topliff fire measured the rate of spread in the cheatgrass. At that point it moved 21/2 miles in 12 minutes," he said.

Whipping along like that, a wildfire could race through the tinder-dry scrub and kill a crew, if the right precautions were not taken. It could burn a ranch house, damage the Goshute Indian Reservation or destroy valuable military instruments.

That's why managers grounded in the science of fire control, using computers and radios and cell phones, are essential.

"It's sort of like we're contracted out, in a way," said Richard Holtz, a National Weather Service meteorologist from Medford, Ore., explaining how he was called in to help. He came to Dugway because a fire expert from the Salt Lake office who might have gone instead was in Texas, where the weather is so dry and hot that fires are a constant fear.

When the fires were burning most fiercely in Tooele County, he said, they were scattered around Dugway Proving Ground, in the Skull Valley area and in Rush Valley. "It was certainly serious," with the heat, dryness and wind, he said. (Holtz was interviewed separately by telephone.)

Holtz described the fire meteorologists' role as, "We're doing our best to give them the most accurate information for temperatures, humidity, wind speed and direction, and also just the general forecast, too."

Working in the headquarters, he uses a laptop computer, which he can use to contact the National Weather Service and pick up weather data. If he were based in the field, he said, he could use a small satellite dish and a portable generator to download information.

He uses this material to make site-specific predictions about weather at particular fires. They "are hopefully helping out for the safety of the firefighters," he said.

What could happen if good weather information wasn't available? He gave this example: A crew is fighting a fire. Light winds are blowing and the crew seems to have it under control. "All of a sudden, you get a thunderstorm, maybe a mile or two away. And all of a sudden, you get one of those downdrafts that come out of the base of the thunderstorm," he said.

"The wind just rushes down. It hits the surface of the Earth and spreads out in all directions . . . Within seconds you can see your winds dramatically increase. That's a huge safety concern." Flames leap up wildly and the fire blows toward the crew.

Weather forecasts also are essential for planning the best way to attack a fire, said Dennis Pebbler, assistant fire management officer for the Moab-Monticello District office of Manti-La Sal National Forest. Based in Monticello, he was called at 10 p.m. Monday when reinforcements were needed to help local fire crews.

Pebbler is a member of the "overhead team," 15 or 20 experts from federal and state agencies who take over in especially dangerous situations.

Reinforcements were needed because fires just keep breaking out and spreading. Many of the crews had already worked 36-hour shifts and were exhausted, said Gardner.

The decision to call in an overhead team and other reinforcements was made by BLM Salt Lake District Manager Glenn Carpenter. It was relayed through the Salt Lake Interagency Fire Center, 1749 W. 500 South, and the Eastern Great Basin Coordination Center, based near the Salt Lake Airport. Finally, the call went to individual dispatch offices.

"When we arrive at the fire, the first thing we try and establish is how long it's been going . . . how big it is," Pebbler said. As he spoke, firefighters were studying a large map on the wall of the briefing room, which was tagged with yellow stick-it notes showing the sites of fires.

Once at Dugway, the newcomers were briefed by local firefighters who had been battling valiantly for several days. "My major concern after that is usually obtaining weather data. And with this fire, I was extremely fortunate because I talked to a fire meteorologist here," he said, referring to Holtz.

The teams put together maps and gathered information about three important factors: type of vegetation, terrain and weather. "The most rapidly changing part of that equation is, `What is the weather?' " Pebbler said.

Weather can change drastically, from day to night. And all three factors affect the way a fire burns.

"Then we figure out some basic things, using a computer model," he said.

Using a laptop, fire planners activate what Pebbler called a fairly simply program, typing in fuel types, wind spread, slope of the landscape and other variables. The model then predicts flame height and fire intensity, which affect the rapidity of the fire's spreading.

The model will help scientists predict where a fire will advance if nothing is done to combat it. They try to map where its perimeter will be six, 12 and 24 hours later. The data helps operations planners decide whether a direct attack is best, if water or retardant should be dumped by helicopters, and where to place fire lines.

If flames will be 4 feet high, hand crews can't be used. "Once you get above that, you're looking at mechanized equipment or people with mechanized equipment in conjunction with retardant," he said.

Perhaps the map will show that the fire is heading toward a road or some natural barrier. If it is a fast, powerful blaze, it might jump right over the road.

But knowing it is heading in that direction, crews can build a firebreak that uses the road as reinforcement. They drive to the barrier hours ahead of the flames and start a backfire that will "burn out from that point ahead of the fire," Pebbler said.

The crews can light a low-intensity fire that slowly burns away from the road, moving into the wind. With crews standing by with fire engines and shovels to put out any sparks that spread beyond the road, it stays under control, blackening a wide swath. When the wildfire arrives it has no fuel and may burn out.

Without a natural barrier or a road, crews can set up a "wet line" of foam instead, and set the backfire there. Or in an emergency they can use bulldozers to "blade" a swath.

Even then, fires can be extremely difficult to control. A juniper tree can suddenly "torch out" and go up in flames. "It will throw pieces of the foliage that will float in the wind for some distance," said Pebbler.

Sometimes this can wipe out a day's work in one huge explosion of drifting sparks that set "spots" of fire - which is called "spotting." But at other times, crews are able to catch them in time.

Technology even helps planners know how much crews can accomplish in their grueling, 12-hour shifts. The operations section, which manages the tactics, has a way to calculate how much a hand crew or a bulldozer can accomplish under given conditions, said Bob Dyson, an expert from Apache-Sitgreaves National Forest, Arizona, who answered the call for help.

In addition, the careful mapping tells where retardant can be used. It is deadly to fish, so lakes and streams must be avoided.

Around midafternoon Thursday a call came over a dispatch radio that another fire had been spotted in Tooele County. Tom Suwyn, section chief of operations, and John Shive, incident commander, stood on the steps of the barracks listening to a radio that was clipped to Shive's shirt. The "Scranton" fire was only a quarter-acre, located at Township 9 South, Range 3 West, Section 8, Tooele County.

A "hot-shot" team was dispatched and the fire was soon out. On Friday, most of the remaining firefighters headed home.