Near Coulee City in Grant County, Washington — The American West (Northwest)
In the Path of Cataclysmic Floods
Massive Glacial Dams and Lakes
During the last Ice Age, a lobe of ice at least a half-mile high blocked the Clark Fork River in Idaho, creating an enormous lake called Glacial Lake Missoula. This ice dam failed - over and over - sending billions of tons of water rampaging across the land.
Raging Journey to the Pacific
The thundering torrent of water, icebergs, and mud raced at speeds up to 60 mph, stripping away tons of soil and rock. The floodwaters raged across eastern Washington, through the Columbia River Gorge, and to the ocean.
How Many Floods Were There?
No one knows for sure, but geologists discovered evidence the Lake Missoula and other glacial lakes filled and emptied many times during the last Ice Age.
(left illustration caption)
At times, the ice dam was more than two miles wide and 30 miles long. Illustration by Stev H. Ominski
(center illustration caption)
Pressure from rising water caused the ice dam to leak and crack. Over time, water began pouring from large fractures beneath the surface, eroding the dam from below until it suddenly
(right photo caption)
You can visit many of the remarkable features created by the Ice Age floods, including Dry Falls, Steamboat Rock, and Beacon Rock. Photo by Lyn Topinka, English River Photography
Erected by Washington State Parks.
Location. 47° 36.431′ N, 119° 21.807′ W. Marker is near Coulee City, Washington, in Grant County. Marker can be reached from Park Lake Road Northeast (Washington Route 17) 2 miles south of U.S. 2, on the left when traveling south. Touch for map. Marker is located in Sun Lakes-Dry Falls State Park, on the east side of the Visitor Center parking lot, overlooking Dry Falls Lake. Marker is at or near this postal address: 34875 Park Lake Road Northeast, Coulee City WA 99115, United States of America.
Other nearby markers. At least 5 other markers are within 13 miles of this marker, measured as the crow flies. Explore Massive Floodscapes! (here, next to this marker); World's Greatest Waterfall... Without Water! (here, next to this marker); Dry Falls (a few steps from this marker); Story of Dry Falls (within shouting distance of this marker); History of the Stratford Area (approx. 13.1 miles away).
More about this marker. Marker is a metal-framed,
Related markers. Click here for a list of markers that are related to this marker. Sun Lakes-Dry Falls State Park
Categories. • Natural Features •
Credits. This page was last revised on February 10, 2019. This page originally submitted on February 8, 2019, by Cosmos Mariner of Cape Canaveral, Florida. This page has been viewed 25 times since then. Photos: 1, 2, 3. submitted on February 8, 2019, by Cosmos Mariner of Cape Canaveral, Florida. • Bill Pfingsten was the editor who published this page.