ELY, Minn.-More than 17 years after a historic windstorm raked the Boundary Waters Canoe Area Wilderness, downing millions of trees, wildfire experts say the danger of increased fires still exists from all that dead and drying wood.
Superior National Forest officials on Wednesday said they will conduct four intentional fires this autumn to remove some of that dead wood under controlled conditions to rob any future wildfire of the fuel to grow out of control.
Two of the fires will be near the Gunflint Trail and the others will be in the Ely area, one near Prairie Portage and one near Crab Lake.
The goal is to break up big, contiguous areas of blown-down trees, so fires remain small enough to battle from air and land, and to keep them from moving out of the wilderness into areas developed with cabins, lodges and homes.
Fall is often the best time in Minnesota for intentional fires because of weather conditions that are often too wet in spring and summer yet are cool enough to keep fires in check.
The intentional fires will be lit in September and October when conditions are just right - not too dry so the fires might spread, but not too wet so the fuel will actually burn and be used up. Wind will be a key factor as well, with fires started only if the wind is blowing away from developed areas.
The July 4, 1999 blowdown snapped and bent trees across Northeastern Minnesota, not unlike storms that ravaged the areas this summer, but on a more devastating scale. It hit more than a half-million acres in the Superior National Forest, including 350,000 acres in the BWCAW.
The Forest Service has worked since the storm to remove trees where possible, either by logging or fire outside the federal wilderness area or by fire inside the wilderness where logging is not an option.
At first, fire experts believed the 1999 downed wood would hold its fuel potential for about a decade before rotting away. But that hasn't happened in some areas, and the dead wood remains ripe to burn.
Some 50,000 acres were initially targeted for intentional fires inside the BWCAW of which about 20,000 still haven't been burned. The Forest Service hopes to burn about 14,000 of those remaining acres over the next two months spread among the four fires, Kris Reichenbach, spokeswoman for the Superior National Forest, told the News Tribune.
Thousands of acres have been "treated" so far to remove the dead wood, "but blocks of concentrated, untreated blowdown fuel remain," Reichenbach said. "Analysis conducted in the last year has made clear that, even 17 years after the storm event, a significant threat of wildfire remains in blowdown areas."
Additional areas are likely to be targeted in 2017.
Several of the state's largest wildfires of the past 80 years have occurred in areas that included trees damaged in the 1999 blowdown, including the massive 93,000-acre Pagami Creek fire in 2011, parts of the the 76,000-acre Ham Lake fire of 2007 and a fire near Knife Lake in 2013. When those fires reached areas of trees blown down in 1999, they burned hotter and faster, Reichenbach said.
Intentional fires can be controversial, however, when they grow larger than their intended acres. In May an intentional fire near Foss Lake, about 10 miles west of Ely, was supposed to be held to 78 acres. But unexpected weather conditions, namely strong winds, pushed it to more than 1,000 acres and out of control, with hundreds of firefighters and several aircraft called in to battle the blaze before it was snuffed.
The fall fires will come at a relatively slow period for visitors to the BWCAW. Some roads may be temporarily closed during the fires, officials noted.