More than 15,000 acres have burned in wildfires in northern Minnesota and northwestern Wisconsin, with dozens of homes and other structures destroyed, officials said Wednesday.

Tuesday's strong winds, high temperatures, low humidity and dry vegetation contributed to the fires' spread. Cooler conditions were in Wednesday's forecast for the region, according to the Minnesota Incident Command System, with slightly calmer winds and higher humidity readings. Rain could arrive as soon as Thursday, with the weekend also in line for precipitation.

The biggest swath of the scorched land and building damage is in the Wisconsin forestland of Douglas and Bayfield counties, where firefighting crews worked through the night to surround what has become known as the Germann Road Fire, a blaze that has so far charred 8,700 acres, the Wisconsin Department of Natural Resources said Wednesday morning.

In northwestern Minnesota, firefighters Wednesday battled a wildfire that burned a yet-to-be-determined number of homes and structures near Menahga.

Firefighters flying over the blaze dubbed as the Green Valley Fire measured it Wednesday morning at 7,100 acres, said command center spokeswoman Jean Goad. But workers have dug a line around the 6-mile-long fire to prevent it from spreading.

Goad said it had been difficult to measure the fire Tuesday because there was so much smoke overhead. Officials were urging people to stay out of the area Wednesday due to smoke.

The fire destroyed some homes and other buildings, but Goad did not have specific numbers.

"Winds are not quite as strong, humidities are not quite as low and temperatures are not quite as high," Goad added, comparing Wednesday to Tuesday. "But it's still a pretty snappy fire day."

The Red Cross opened two shelters for residents evacuated from homes in Wadena and Hubbard counties. A fire northeast of Camp Ripley also threatened structures.

Nearly 100 residents of a nursing home and assisted-living center in Menagha returned unharmed Wednesday morning after spending the night on cots in a high school gym 9 miles south in Sebeka.

Administrator Clair Erickson noted that the precautionary evacuation came only hours after a Nursing Home week event in which the staff provided s'mores to residents as part of a "campout."

"We told them we were celebrating Nursing Home Week with a slumber party," he said.

Highway 71 was closed from Menahga to Park Rapids, about 10 miles north of Menahga. Additional road closures in the area are being contemplated.

As of 6 a.m., no portion of the fire could be classified as contained, the command center added.

Gov. Mark Dayton signed an emergency order Tuesday night to facilitate the fight against more than 25 wildfires that have broken out around the state in recent days, including two large fires that burned a combined 4,900 acres about 35 miles west and 45 miles northwest of Red Lake, but which had not destroyed any structures.

At Dayton's direction, the Minnesota National Guard has deployed two helicopters and two large tactical trucks as part of the efforts to douse the Green Valley Fire.

Guard Army Maj. Bruce A. Kraemer said that 22 soldiers serving as "air crews, maintenance and fuel support teams are currently on state active duty assisting with wildfire suppression operations."

The Salvation Army was at Menahga City Hall during the day serving 200 meals, snacks and water to firefighters and other first responders. The charity will serve dinner to crews Wednesday night at Blueberry Pines Golf Club, just north of Menahga.

"The Salvation Army has volunteers, supplies and extra mobile kitchens on standby at our Twin Cities headquarters," said Capt. Scott Strissel, leader of the Brainerd Area Salvation Army. "We are ready and willing to increase our service if called upon."

In Wisconsin, the Germann Road Fire, now burning for two days, is northern Wisconsin's largest in 33 years, according to the state DNR. How the fire started has yet to be determined.

"With wind out of the northwest, our concern has been the southern and eastern flanks of the fire," said Wisconsin DNR incident commander Larry Gladowski. "We should have control shortly. It was 90 percent contained at 7 a.m. Now with hot, dry and windy conditions forecast for today, we are asking people to be extremely careful so no more destructive fires are started."

About five dozen residents were moved to Drummond High School from Loon Lake, Sand Lake, Murray Lake, Potowatomi Estates, Rock Lake, Beauregard Lake, Catherine Lake, Ellison Lake and the Village of Barnes.

The Wisconsin DNR reported 47 structures have been lost, including 17 homes, 15 garages, nine out buildings and six unknown. Firefighters have saved 77 structures, including 42 houses.

Battling the flames have been 19 fire departments assisted by the Wisconsin DNR and the U.S. Forest Service.

There are more than 50 fire trucks on the scene, and they were awaiting the arrival of two water bombers from Ontario and two helicopters from the Wisconsin National Guard equipped for water drops.

The last major forest fire in northern Wisconsin, called the Oak Lake Fire, occurred April 22, 1980, and consumed 11,418 acres of forest.

Bill McAuliffe • 612-673-7646 Paul Walsh • 612-673-4482