A fast-growing wildfire forced over 42,000 people to evacuate near Reno, Nevada, over the weekend, while more than 40,000 others remained under evacuation warnings.

The blaze, dubbed the Hawk Fire, started northwest of Reno on the morning of Aug. 22 and quickly grew to more than 15,000 acres by the afternoon of Aug. 23, according to the National Interagency Fire Center. Firefighters expect the fire to spread to the northeast, “impacting multiple major thoroughfares, structures, businesses” and infrastructure in Stead, Nevada, the fire center posted in an update.

Nevada Gov. Joe Lombardo declared an emergency for Washoe County, which includes Reno and the northeast portion of Lake Tahoe. “This is an active and rapidly evolving situation, and I urge everyone in the affected areas to remain vigilant and follow the direction of local officials,” said Lombardo in a statement shared on social media.

The Hawk fire had burned an undetermined number of structures, according to Shane Akerson, a battalion chief with the Truckee Meadows Fire Protection District during an Aug. 23 briefing. The fire, which started in the Peavine Peak area of the Humboldt-Toiyabe National Forest, was human-caused and the source of the ignition remains under active investigation, Akerson said. At least six people had been injured, including three civilians and three first responders.

No other details were released about how the fire started, and no estimate was available on the morning of Aug. 23 for the number of structures burned because of the active fire situation, according to the fire protection district.

More than 7 million acres burned in US in 2026

The Hawk Fire is the latest large wildfire across the nation this summer to exhibit “extreme fire behavior,” according to reports provided to the interagency fire center. Wind-driven flames in the fire made “significant runs through light, flashy fuels” over the weekend, according to the fire center’s database.

The fire was one of 200 new wildfires reported across the nation on Saturday, Aug. 22, with large wildfires burning in 18 states, according to the fire center’s daily situation report. The total burned acres across the nation this year have climbed to 7.7 million, 3 million acres more than the 10-year average over the same period.

The Hawk Fire is at least the third wildfire to affect northern Nevada in recent weeks. Together, the Bug and Stallion fires burned more than 100,000 acres, the Reno Gazette Journal, part of the USA TODAY Network, reported.

Nevada evacuations cover a large area, border California

According to the evacuation tracking site Perimetermap.com, evacuations for the Hawk Fire covered an area from Interstate 80 north to U.S. Hwy. 395 and west to the Nevada/California state line.

In addition to the more than 800 firefighters deployed on the fire, hundreds of law enforcement personnel were on scene, and members of the National Guard were being deployed to assist, said Washoe County Sheriff Darin Balaam.

Balaam encouraged those in areas who had been asked to be ready to evacuate to go ahead and evacuate if they could, describing a tense situation in one neighborhood on Aug. 22 as fire overtook a neighborhood where people were trying to evacuate, and firefighters were trying to get in.

In a social media post, Reno Police Chief Corey Sulferino urged residents not to reenter evacuated areas until the evacuation orders are lifted.

In California, Gov. Gavin Newsom said the state is monitoring the fire and coordinating with state and local agency partners. He urged California residents in the affected areas to follow guidance from local officials.

Officials announced closings for most Washoe County schools on Aug. 24, while the University of Nevada said in a social post that its operations would continue normally, with none of its campuses under evacuation warnings.

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Contributing: Reuters

Dinah Voyles Pulver, a national correspondent for USA TODAY, covers climate change, weather, wildfires and other news. Reach her at dpulver@usatoday.com.