Teton Wilderness, WY F4 Tornado (1987)

Photo from Fujita’s paper showing a swirl pattern to the trees.

On July 21, 1987, an F4 tornado tracked 24 miles across the Teton Wilderness into Yellowstone National Park. Over 1,000,000 trees were knocked down as the tornado slashed its way across mountain tops up to 10,000 feet high, and through valleys. This is the highest altitude in the US that a violent tornado (F4/F5) has ever occurred.

Detailed Summary