Jean Goad of the Minnesota Department of Natural Resources said the Nimrod-area fire, fanned by gusting winds, was 3 miles wide at one point as it burned through grass, trees and swampland, WCCO-TV, Minneapolis reported. Helicopters and airplanes were being used to drop water on the flames.
The fire had burned a mobile home used as a hunting shack and an attached garage at a residence. No injuries were reported.
In New Jersey, a wildfire that had burned about 1,000 acres of the Pinelands in Burlington County was about 50 percent contained by Monday afternoon, newjerseynewsroom.com reported. Winds also were hampering firefighters' efforts there.
The Pinelands blaze had posed a potential threat two a couple dozen houses, though no mandatory evacuations had been ordered, officials said.
Another fire at Joint Base McGuire-Dix-Lakehurst in Burlington County had burned about 300 acres, the news Web site said.
No one was reported hurt in the New Jersey fires.
In Virginia, a wildfire burned about 700 acres in Page County, WHSV-TV, Harrisonburg, Va., reported.
"We could see the flames, and as the wind would pick up you could see the flames shoot up, and it reminded you of a volcano. It looked like lava pouring down the side of the mountain," Crystal Knighton, who lives nearby, said.
The state Forestry Department said the fire was totally out of control Monday afternoon.
Wildfires also were burning in Florida. The Florida Times-Union in Jacksonville reported one fire, started by a lightning strike, was about 30 percent contained after burning nearly 12,000 acres of mostly forest land at the Columbia-Baker county line.
Another fire had burned 450 acres in Putnam County and was 90 percent contained.
Florida Gov. Rick Scott told the newspaper he hoped "there will be "a lot of rain, then have no hurricanes."
"Last year we had wildfires and lost two firefighters [Josh Burch and Brett Fulton, while fighting a June fire in Hamilton County], so we all have to be on the lookout," Scott said. "The state is dry right now, so we can all pray for rain. In the meantime we have to make sure everybody's cautious."
It's Wildfire Awareness Week in Florida. So far this year, more than 1,100 wildfires have burned 20,000 acres statewide, Agriculture Commissioner Adam Putnam said. The Orlando Sentinel reported there were 64 fires active in the state Monday.
"Over the coming weeks and months, it is likely that Florida will experience very high to extreme wildfire danger due to these dry conditions," Putnam said. "It is critical for Floridians to take steps to ensure their own safety."