Firefighters on Thursday reported big gains in controlling a wildfire that had forced residents to flee this scenic eastern Sierra Nevada community.

A shifting wind blew flames back onto themselves, and the fire was 50 percent contained early Thursday, said fire spokesman Mark Struble.

The blaze's official size was revised to around 1,000 acres because of more accurate mapping.

The fire, which was sparked by lightning last Friday, had been nearly contained before it was fanned by 65 mph wind gusts and roared back to life Tuesday.

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About 270 people who had to flee the town and a Marine Corps family housing complex were allowed to return to their homes Wednesday.

A 40-mile stretch of U.S. Highway 395, a key road along the Sierra front, also reopened Wednesday, though traffic was detoured in the immediate burn area.

The same front that fanned the fire on Tuesday brought colder temperatures and some moisture to the region, aiding firefighters. Temperatures for the past two nights dropped into the 30s Fahrenheit, and snow dusted some foothill areas.

"Once that front blew through, the winds shifted around more out the north, and started pushing the fire back into itself," Struble said.

Air tankers and helicopters that were grounded Tuesday by the fierce winds were back in action Wednesday. More than 600 firefighters remained on the lines.

Fire officials hoped to have the blaze fully contained by Tuesday.

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