Out-of-control wildfire destroys town of Greenville, California, as dry, gusty conditions encourage rapid spread

Wildfires in the West have spread so rapidly amid continuing dry, gusty conditions that a Northern California town has been destroyed.

Firefighters had made progress on containing the Dixie Fire, the largest in California, which has been burning near Feather River Canyon for weeks. But after the fire jumped containment lines earlier this week, it exploded, consuming an additional 48,000 acres on Wednesday alone.

As of Friday morning, it is burning in four California counties: Butte, Plumas, Tehama and Lassen.

The blaze has destroyed "well over 100 homes" and many businesses in the downtown neighborhood of Greenville, about 150 miles northeast of Sacramento, Plumas County Sheriff Todd Johns said at a press conference Thursday night. At least 31,000 people have been evacuated.

Dramatic images show multiple structures engulfed in flames. The historic area of Greenville has been destroyed, leaving nothing but rubble behind, according to photographers who examined the ruins.

One photographer saw a gas station, hotel and bar completely burned to the ground, according to The Associated Press.

One witness told the AP that she fled with a dog and two horses as she watched clouds grow from the west side of a lake where she was camping.

"The flames were huge," Dawn Garofalo said. "They must have been 500 feet high. Scary."

Almost 100 wildfires are currently burning in the West, with the majority stretching from Northern California to western Montana, and there's potential for more to spark as existing ones spread.

Much of the West is under critical fire danger alerts, with warnings issued for nine states from California to Colorado due to dry lightning threats and gusty winds that could reach up to 40 mph. Red flag warnings remain in effect through Thursday evening for dry and windy conditions.

The Dixie Fire has now scorched through more than 361,812 acres -- more than 565 square miles --- since it sparked on July 13 and is 35% contained.

The River Fire near Colfax, California, which prompted evacuations for several thousand residents, had burned through 2,600 acres by and is 15% contained.

At least 76 structures have been destroyed by the River Fire and another 20 damaged, according to Cal Fire.

One firefighter and two civilians have been injured in the blaze as of Friday morning.

Evacuations also have been ordered for the Monument Fire in Big Bar, California, and McFarland Fire in Wildwood, California. Both fires were spreading on Thursday.

Temperatures in Northern California, where the fires are burning, are expected to get hotter on Thursday, with Redding forecast to approach 100 degrees over the next few days.

Thermal, California, about 130 miles east of Los Angeles, reached 122 degrees on Wednesday, making it the hottest August temperature ever recorded in the region.

Record highs also were reported in Palm Springs (122 degrees) and Kingman, Arizona (107 degrees).

Excessive heat warnings are continuing for Nevada, California and Arizona, where temperatures are expected to reach 115 degrees on Thursday.

ABC News' Marilyn Heck, Melissa Griffin, Max Golembo and Jenna Harrison contributed to this report.