ST. GEORGE, Utah — Firefighters battled in hot, dry and windy weather Sunday to contain wildfires that have prompted evacuations, closed a major highway and covered much of southwest Utah with a dark, smoky haze.

Officials said the blaze about 20 miles north of St. George grew from 2,000 acres to 8,000 acres in less than 12 hours, and by late Sunday was within five miles of New Harmony.

"That's going to be our nightmare," said fire commander Taiga Rohrer, watching plumes of smoke billowing off the Black Ridge Mountains, about 280 miles south of Salt Lake City.

As Lea Twitchell and her family prepared to evacuate their New Harmony home, her thoughts were with her son, Luke, a firefighter for the Bureau of Land Management fighting the blaze.

"He just started on that crew, and I'm a little nervous because we haven't heard from him," she said Sunday.

She said smoke and ash had already built up a layer on their cars. "It's a little bit irritating to breathe," she said.

The fire was started Saturday by lightning strikes and at one point jumped Interstate 15, forcing state officials to close the highway, the major route between Salt Lake City and Las Vegas. It reopened Sunday morning but was later closed again while fire crews burned an 8- to 10-mile swath of land adjacent to the highway to prevent it from jumping the road again.

The fire was fueled by temperatures in the high 90s, wind gusts of 25 mph and low humidity.

About 20 miles to the southwest, firefighters were continuing to battle a blaze that has consumed nearly 70,000 acres. Ground crews worked to cut off the head of the fire and were using a bulldozer to cut a firebreak through the rough, hilly country.

Four helicopters were picking up as much as 1,000 gallons of water from two nearby reservoirs to douse the flames.

"We've had very low flame heights and really no smoke, so we've modified our attack plan," fire information officer David Olson said.

Elsewhere, firefighters struggled to extinguish blazes in California, Arizona, Nevada, Alaska and Washington state that have consumed more than 350,000 acres.

In southern California, firefighters near Kelso made progress against a wildfire that has charred 67,000 acres in the rugged Mojave National Preserve, which includes historic mines and sites with ancient Indian pictographs. The blaze has destroyed five homes and two cabins built in the late 1800s and threatened several dozen other homes.

Firefighters had the blaze 65 percent contained Sunday night with the help of lighter-than-expected winds, said Capt. Greg Cleveland, a spokesman with the Southern California Incident Management Team.

A brush and grass fire that had charred more than 92,000 acres in Arizona by Sunday was only about 20 percent contained. Arizona fire officials were also concerned about a threat of more thunderstorms generating wind and lightning.

About 900 firefighters were working at the site northeast of Phoenix.

Firefighters in Nevada reported progress Sunday containing a 31,600-acre wildfire in the mountains southwest of Las Vegas. More than a dozen other blazes were also burning in the southern part of the state.

In Washington state, a wildfire had blackened up to 22,000 acres of grass and wheat fields by Sunday in Walla Walla County, with smoke from the fire reported as far as Spokane, about 100 miles north. Firefighters had a line around 75 percent of the fire by late Sunday afternoon, officials said.

No property was threatened and there were no reports of injuries.

And in Alaska, fire crews continued to battle a blaze that had claimed 80,000 acres near the Sheenjek River about 145 miles north of Fairbanks. The fire, which started June 12, was about eight miles from Fort Yukon, a town of about 600 people.

Source: Associated Press