Three wildfires in northern Minnesota’s Arrowhead region have grown from a few hundred acres to several thousand, with new evacuations and reports of destroyed buildings increasing by the day.
Red flag weather warnings, signaling conditions are ripe for fires to spread quickly and grow out of control, were in effect across dozens of Minnesota counties. By late in the week, cooler weather and rain had slowed the spread.
Here’s the latest information on the fire perimeters as of midday Friday, May 16.
Fire growth has slowed
The two largest fires — the Camp House and Jenkins Creek fires — grew quickly in the initial days of spread but have slowed thanks to cooler weather and rain.
Spruce budworm infestation fuels flames
Part of what is driving the easy spread of the fire is an old pest: spruce budworm.
After they hatch, spruce budworms larvae can defoliate mature trees like balsam fir and spruce until they are killed.
Humans’ work to suppress fires may have also exacerbated the budworms’ growth, according to the DNR’s 2024 Forest Health Annual Report. Stopping natural fires allows fir and spruce forests to grow older and denser, which means more food for budworms.
Spruce budworm outbreaks have been reported in Lake County, Cook County and St. Louis County. The insects infected more than 700,000 acres of forest last year, marking the largest impact recorded since 1961.