Ice Age Floods of Change

At the end of the last Ice Age, 18,000 to 15,000 years ago, an ice dam in northern Idaho created Glacial Lake Missoula stretching 3,000 square miles around Missoula, Montana. The dam burst and released flood waters across Washington, down the Columbia River into Oregon before reaching the Pacific Ocean. The Ice Age Floods forever changed the lives and landscape of the Pacific Northwest.

Columbia River runs through dark green hill sides illuminated by a ray of light on a cloudy day.
Learn about the Trail

Learn the story of the Missoula Floods.

basalt hillside has green trees in front of it.
Places To Go

Explore Ice Age Floods National Geologic Trail and the 4 states which the Missoula Floods flowed through.

New Ice Age Floods Interactive Map
New Ice Age Floods Map

New Ice Age Floods National Geologic Trail Interactive Map

Last updated: April 4, 2024

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Contact Info

Mailing Address:

Program Manager
Ice Age Floods National Geologic Trail
1008 Crest Drive

Coulee Dam, WA 99116


(509) 237-9722

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