PHOENIX, Arizona (AP) -- Firefighters in the southwest U.S. got an unexpected boost from lighter winds and higher humidity as they tried to stop a wildfire in central Arizona from reaching four nearby communities and vulnerable forests.
The fire had charred 199,370 acres (80,700 hectares) by Thursday night to become the second-largest wildfire in the state's history. The blaze was just five miles (8 km) east of Black Canyon City and Interstate highway 17, connecting the cities of Phoenix and Flagstaff.
Elsewhere in the United States, the National Interagency Fire Center said Thursday that 22 active large fires were burning across nearly 1 million acres in Alaska, Arizona, Colorado, Nevada, New Mexico and Utah.
In Nevada, firefighters stopped wildfires short of a southern Nevada railroad town and said huge blazes burning in a vast area inhabited by tortoise and bighorn sheep were about half contained.
No large-scale evacuations were planned in the central Arizona fire, although officials said they might need to close the highway periodically through the Independence Day holiday weekend if the smoke worsens.
''It's looking real good,'' said fire spokeswoman Emily Garber. ''Our big concern is protecting the east flank and Black Canyon City. We think we have enough lag time to do so.''
Residents, meanwhile, watched and waited.
''You might as well take it with a grain of salt, a sense of humor, and pray for the best,'' said Scooter Grider of Black Canyon City, a town of about 2,700.
Almost 1,700 people were fighting the fire. Crews stationed between the fire's western flank and Black Canyon City were trying to push the fire south into an area already scorched by an earlier fire. Firefighters also helped residents clear brush from around their homes, in case fire lines don't hold.
To the north and east, firefighters worked to stop flames from jumping the Verde River and reaching the city of Camp Verde, about 25 miles (40 kilometers) away.
Authorities worried that if the fire jumped the river, it could also move closer to the towns of Pine and Strawberry, which are just 3 miles (8 kilometers)apart and combined have fewer than 5,000 year-round residents. The forest surrounding the towns has been hard hit in recent years by tree-killing beetles, leaving plenty of dead trees as fuel.
Associated Press Writers Amanda Keim in Black Canyon City and Ken Ritter in Las Vegas contributed to this report.