Storm Damage

The July 4th Blowdown of 1999
On July 4, 1999 a windstorm of historic proportions tore through Superior National Forest, especially the north central and north east Boundary Waters. Winds of more than 90 miles an hour blew down millions of trees over a 350,000-acre area. Hundreds of campsites and portages were hit hard, and a heroic effort by hundreds of rescue personnel, Forest Service staff, and volunteers evacuated everyone from impacted areas and clear trails and campsites. Miraculously, no one was killed by the storm, a fact that is hard to believe when you view the scale and extent of the damage.

This incredible storm changed the Wilderness for years to come. It has created the opportunity for new experiences, but raises new risks for BWCAW visitors. One of the most significant risks posed by the blowdown is that fuel loads in the forest have dramatically increased. A Forest Service team examining the storm impacted area found that fuel loads on the forest floor increased from between 5 and 20 tons per acre between 50 to 100 tons per acre over many thousands of acres.

The Forest Service also concluded that lightning strikes will be more successful at igniting wildfires in the blowdown, and fires that start are more likely to exhibit extreme fire behavior. Due to the expected fire intensities and flame lengths in these heavy fuels, fires will be much more difficult to control during a wider range of weather conditions. Fires will be larger and will occur under more moderate weather conditions because of the high fuel density, the higher fire-spread rate expected under moderate fire weather conditions, the potential for plume-dominated fire, and the difficulty in controlling wildfires in blowdown.

According to Forest Service analyses, the elevated risk of extreme fires and of a wildfire exiting the BWCAW will remain for a number of years. Under natural decay processes dead and down woody fuel currently on the forest floor will not return to pre-blowdown conditions for 15 years or more in hardwood stands and 30 or more years in conifer stands. The Forest Service Fuels Risk Assessment states that it is highly likely that wildfires will occur in many of these areas before the downed materials have completely decayed.