The last Ice Age ended somewhere between 12,000 and 17,000 years ago and went out with a series of catastrophic floods that permanently marked much of the northwest United States.
Its effects were particularly dramatic in parts of Washington, Oregon, Idaho, and Montana, known as the Ice Age Flood Trail.
Why Is It Famous?
The unique landscape and large expanse of mountains and canyons have led to the area’s fame. Some scientists believe more than 40 floods occurred to create the dramatic topography.
The Ice Age Floods National Geologic Trail is a network of routes that extend across parts of Idaho, Montana, Oregon, and Washington. There are several centers for interpretation and study scattered across the trail.
The trail for touring is still in development. It will include routes throughout the Pacific Northwest where the Ice Age Floods had the largest impact.
The Glacial Lake Missoula in Montana is included. Both the Clark Fork River and Lake Coeur d’Alene of Idaho are included as waters flooded there periodically. Several areas along the Waterville Plateau in Washington State will be included as well.
Flood erosion features such as Crab Creek, Drumheller Channels, Channeled Scablands, and Corfu Slide in Washington State will also be part of the Ice Age Floods National Geological Trail. Land features you can expect to see are mountainous regions with valleys, shelves, and dry falls.
Events in Time
A piece of the Cordilleran Ice Sheet moved from Canada to the Idaho panhandle region during the last Ice Age known as the Wisconsonian Ice Age around 100,000 years ago. This created the Glacial Lake Missoula Floods.
The Missoula Floods happened periodically when the ice dam broke and released waters across Eastern Washington and Idaho, down to the Columbia River Gorge. This happened about 40 times for 2,000 years. These waters traveled as fast as 60 mph, draining the lake in just two days at times.
The topography is dramatic due to a natural disaster thousands of years ago. Today, it will be marked as the first geological trail in America. It is set up for studying and interpreting the Glacial Lake Missoula Floods.