Despite the adverse conditions and extreme fire behavior, some progress was made on the Beaver Creek Fire's south end, where crews conducted mop-up along the borders of blackened foothills west of the Hailey.
Lightning ignited the blaze Aug. 7. Fire officials estimated it grew to 144 square miles Friday night, fed by dry timber and underbrush. But they expect a more accurate size assessment after a plane with infrared cameras flies over the burn Saturday night.
The fire is 6 percent contained.
More than 700 firefighters have been deployed to the mountains west of this affluent region, where celebrities like Arnold Schwarzenegger, Tom Hanks and Bruce Willis own pricey getaways. Five more hotshot crews arrived Saturday, and more are expected to arrive this weekend to continue focusing on protecting homes in a sparsely populated county.
"It was a good day from the standpoint that we had no injuries, no lives lost, and no homes and property burned," fire spokeswoman Lucie Bond said. "Firefighters have been going house-to-house to decrease the risk. We're simply not going to leave homes unprotected."
Elsewhere, in northern Utah, about 10 homes were destroyed when a wildfire raced through the community of Willow Springs late Friday. As of midday Saturday, the Patch Springs Fire had burned more than 50 square miles. It was 20 percent contained.
The Beaver Creek Fire is the nation's top-priority wildfire, in part because it's burning so close to homes and subdivisions. Early Saturday, the firefight was hampered by thick smoke that engulfed Hailey, a town with 7,900 inhabitants 14 miles south of Ketchum, home of the Sun Valley Ski Resort.
Smoke stretching across the tight Big Wood River Valley also grounded the air attack on the blaze, putting more pressure on fire crews building fire lines on the ground. But by midday, the smoke cleared enough to scramble helicopters that targeted fires burning in the mountains and foothills that shoulder Hailey and north to Ketchum.
Fire managers also turned to a huge DC-10 tanker to resume retardant drops all across a fire that is burning hotter and faster than the Castle Rock Fire that threatened these towns in 2007.
"This fire is consuming everything," fire spokeswoman Madonna Lengerich said. "The fire is so hot, it's just cremating even the biggest trees."
Ketchum, with a population of 2,700, and Sun Valley, with 1,400 people, were under "pre-evacuation orders," with authorities telling residents to be ready to leave if necessary. Many in those towns heeded the advice as the exodus heading south on Highway 75 continued to slow traffic through the valley.
Ketchum's tony retail and dining districts, normally buzzing this time of year with tourists and summer residents, resembled a ghost town. Dozens of retail shops, bars, outdoor cafes and restaurants on the town's main street closed their doors Saturday. Even The Casino, the city's oldest bar, closed its doors to the surprise of residents. The Casino was established in 1936.
"I've never seen it like this," said Dale Byington, general manager and 23-year veteran of The Sawtooth Club. The business was one of a handful of restaurants open on or near Main Street, but it closed early Saturday because of a lack of business.
"The only reason I opened was to give people here a place to go and get some food and drink, but that's not going to happen," Byington said.
Fire officials are hoping the weather cooperates Sunday, when temperatures are expected to cool.
In Utah, fire managers eyed the weather Saturday as crews continued battling several blazes, including the Patch Springs Fire in Tooele County.
The fire was relatively tame until Friday, when shifting winds pushed it over state Highway 199. Flames raced through Willow Springs, about 60 miles southwest of Salt Lake City, and forced the sudden evacuation of homes there and in the community of Terra, as well as a campground.
The highway and campground remained closed Saturday, but residential evacuations were being lifted.
Near Park City, Utah, crews reported progress battling a fire that destroyed eight homes earlier in the week.
That blaze has burned about 3 square miles and was 58 percent contained Saturday, spokeswoman Julie Booth said.
Copyright 2013 The Associated Press.