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 that stretched 3,000 square miles into Montana. The dam burst and released flood waters across Washington, down the Columbia River, back flooding into Oregon, before reaching the ocean. This happened perhaps a 100 times and changed the lives and landscape of the Pacific Northwest.

NASA graphic image showing the landscape impacted by the floods

Ice Age Floods National Geologic Trail

NASA helps us see the landscape impacted by the floods.

This is a graphic representation of where the flood waters went.

Washington Geological Survey Floods Map

Washington Geological Survey/Washington State DNR

Last updated: January 14, 2022

Contact the Park

Mailing Address:

Program Manager
Ice Age Floods National Geologic Trail
1008 Crest Drive

Coulee Dam , WA 99116


(509) 237-9722

Contact Us


Stay Connected