On July 4, 1999, in the Boundary Waters Canoe Area Wilderness, a bizarre confluence of meteorological events resulted in the most damaging blowdown in the region's history. Gunflint Falling tells the story of this devastating storm from the perspectives of those who were on the ground before, during, and after the catastrophic event.

The forecasts in Duluth predicted the day would be "warm and humid. Partly sunny with a 30% chance of thunderstorms." But as the evening settled, the first eyewitness accounts began to tell a terrifying story. Friends camping on Lake Polly watched in wonder as the sky turned green and the winds began to whip. They scrambled to pull canoes on shore when a tree snapped and struck one of them in the head, rendering her unconscious. Three women enjoying their last day of a camping trip took shelter in their tent as winds increased. Water drenched the nylon walls as trees crashed around them, one flattening the tent and pinning a woman beneath it. A family vacationing at their cabin dodged falling trees and strained against straight-line winds as they sprinted from the cabin to the safest place they knew: a crawl space underneath it. They watched as trees snapped, their twisted root balls torn out of the earth. By the time the storm began to subside, falling trees had injured approximately sixty people, but amazingly, no one died.