By David Bailey
MINNEAPOLIS (Reuters) - A wind-stoked wildfire in a pristine area of northeastern Minnesota popular with canoers and wilderness campers grew five-fold in a day to more than 60,000 acres on Tuesday, threatening 36 homes and sending a smoke trail as far south as Illinois.
Ignited by lightning on August 18 about 14 miles east of Ely, Minnesota, the fire in the Boundary Waters straddling the border with Canada made a 16 mile wind-driven run to the east on Monday, becoming one of the biggest recent blazes in the Superior National Forest, the U.S. Forest Service said.
The rapid spread of the fire forced residents to clear 36 homes in Isabella, Minnesota, and authorities have called in airborne water drops to slow its spread. No injuries had been reported or structures burned as of Tuesday afternoon.
Airplanes from Canada and four Minnesota National Guard "Blackhawk" helicopters with supporting crews have joined the nearly 200 firefighters now assigned to contain the blaze.
Known as the Pagami Creek Fire, the blaze ballooned from about 11,000 acres Monday on strong winds from an unexpected direction and dry conditions, said Lisa Radosevich-Craig, a spokeswoman for the U.S. Forest Service.
"Typically more than an inch of rain would have fallen in this area during this time but didn't," Radosevich-Craig said of the last few weeks. "Where the winds are coming from and the strength of the winds is unprecedented."
The forest service expected the wind to remain strong out of the northwest and west again Tuesday, with little or no rain, adding to concerns about the fire.
The National Weather Service issued a special weather statement, saying winds out of the north associated with a Canadian cold front were pushing smoke 400 miles or more south of the blaze into the Chicago area.
Forecasters expect the smoke and "distinct burning odor" to continue to spread south into northwest Indiana over the next day or so and said emergency managers in some affected areas were warning people with breathing difficulties to take precautions, the weather service said.
A hazy sky and smoky smell covered much of southeastern Wisconsin Tuesday and the Milwaukee Brewers baseball team was expected to keep the retractable roof at its Miller Park stadium closed for a dry night ballgame because of the smoke.
"It's following a perfect path to come to Southeastern Wisconsin," said meteorologist Morgan Brooks of the weather service based in Sullivan, about 50 miles west of Milwaukee.
Around the fire, several roads were closed as were many entry points into the wooded region popular for its extensive rivers and lakes, remote camp sites and hiking trails.
The fire grew very slowly to a handful of acres for more than a week after the lightning strike, jumping to 130 acres on August 26 because of strong winds, she said.
Public safety crews over the weekend had moved 120 campers from south of the fire and the eastern edge of the fire and were moving visitors from risk areas on Tuesday. Some campers and hikers were collected over the weekend by float planes.
Minnesota Governor Mark Dayton ordered National Guard helicopters to the region to assist in the firefighting. Some 25 National Guard troops and four helicopters were dispatched.
In 2007, the Ham Lake Fire burned about 70,000 acres in the United States and Canada along the Minnesota-Ontario border.
(Additional reporting by Brendan O'Brien in Milwaukee and James B. Kelleher in Chicago)