Damaging Wind in Minnesota, July 4, 1999

A widespread convective windstorm called a "derecho" swept across the Arrowhead region of northeastern Minnesota on July 4th. Strong, straight-line winds in excess of 80 mph devastated a large area of the Boundary Waters Canoe Area Wilderness (BWCAW). This area is very sparsely populated, but thousands of trees in an area approximately 30 miles long by 12 miles wide, or about a quarter million acres, were levelled. The timber loss was estimated at .5 to .75 million cords and valued at between $12 and $18 million. Because much of the timber was torn and splintered, the salvage value was estimated to be only about $5 million. The hardest hit area was from Moose Lake in the BWCAW to near ELY to the Gunflint Trail, where hardly a tree was left standing. Twenty people, injured by falling trees, had to be airlifted to area hospitals. A man was crushed under a tree for four hours, and a woman was pinned under a tree with both legs broken. The state of Minnesota estimated the cost of other damage and debris clearance for Lake and Cook counties at nearly $5 million.