Five of the top priority wildfires are in Utah, where crews are fighting the biggest fire in state history, which had spread across 514 square miles by Wednesday, authorities said. The fire about 120 miles south of Salt Lake City was 30 percent contained, officials said. National Weather Service forecasters said they expected the high winds to continue into Thursday, which could hamper containment efforts.
In southeastern Utah, the nation's top-priority fire burned 3 square miles near gas wells and within a half-mile of one of Utah's deepest coal mines and its methane vents. "We'll stop the fire before it gets that far," said incident commander Bob Prodahl. Officials said it was about 50 percent contained Wednesday night.
A smaller brushfire broke out in the Ogden foothills overnight and burned dangerously close to homes, reports CBS station KUTV. A canal road stopped the blaze going any further.
Nevada's largest blaze — near the Idaho line — had grown to about 124 square miles Wednesday and was 40 percent contained, Elko Interagency Dispatch Center Manager Bill Roach said. Heavy rain fell in western Nevada, dousing a handful of lightning fires around Reno, authorities said.
In southern Idaho, more than 230 firefighters had an 81-square-mile fire about 40 percent contained.
After a week of battling high temperatures, gusty winds and lightning, firefighters caught a break when a storm system bringing higher humidity helped them tame wildfires throughout California.
The state's largest blaze in the Inyo National Forest was in "mop-up mode" by Wednesday evening, and officials there were sending crews to assist elsewhere, said fire information officer Jim Wilkins.
Crews in South Dakota were hoping cool and cloudy weather would help them battle a blaze that killed one homeowner and destroyed 30 houses. The blaze had covered more than 15 square miles and was 40 percent contained Wednesday.
In Arizona, a fire that threatened buildings at the Kitt Peak National Observatory near Tucson was 50 percent contained Wednesday at 7,267 acres, about 11 square miles, and was unlikely to threaten any buildings, authorities said.
In northwestern Arizona near the Utah border, firefighters got help from cooler weather and a bit of rain while fighting a 22,387-acre fire that had burned down a small garage or shed and threatened five ranch houses and several government buildings. That fire was 20 percent contained, officials said.
In Washington, authorities said they had 100 percent containment on two wildfires near Wenatchee, about 100 miles east of Seattle, and 90 percent containment on a wildfire further north in Okanogan County.
Another round of record heat was forecast in the Northwest, adding to the problems faced by crews battling fires in Washington. High temperatures ranging up to 107 degrees were forecast for Thursday and Friday in south-central Washington.
Officials declared California's 35,000-acre Inyo fire mostly under control, but said it would remain listed at just 80 percent containment as the western flank continued burning in an area with little vegetation that's too treacherous for crews to access, Wilkins said.
Gov. Arnold Schwarzenegger declared a state of emergency in Inyo County on Wednesday to free up state resources for fighting the blaze and helping residents of Independence whose water supply was contaminated by the fire.
The Inyo fire has injured 11 firefighters and destroyed six homes in the area north of Mount Whitney, the tallest peak in the continental U.S.
Near the central coast, firefighters continued to cut lines Wednesday to corral a 10,400-acre blaze in the Los Padres National Forest that was 37 percent contained, said fire information officer Tony Guzman.