Washington is a state of dramatic landscapes: beautiful farmlands, orchards, vineyards, and scenic mountains, rivers and lakes. There are the scablands, lava flows, canyons and coulees, buttes, dry cataracts, boulder fields and gravel bars too.

These latter landscapes were puzzling to geologists.

In 1923 geologist Harlen Bretz sparked one of the biggest debates in geologic history when he proposed his Ice Age Floods theory. He spent decades tramping across the state meticulously documenting evidence to support his theory that massive Ice Age floods carved the Channeled Scabland of eastern Washington.

“Science is human observation and human reason coming to conclusions based on educated guesses.”

“The geologic community only ridiculed and scorned his work…until they saw the evidence themselves.”

I am more history oriented than science oriented, but I like a good mystery and the flood story intrigued me. For years I have wanted to follow the path of the floods to see the evidence for myself.

Accompanying us on our road trip was Washington Rocks! A Guide to Geologic Sites in the Evergreen Site by Eugene Kiver, Chad Pritchard, and Richard Orndorff. It was a really helpful resource with great photos and explanations to make sense of the sites we visited.

Palouse Falls State Park: “The Palouse River once flowed through Washtucna Coulee, a massive valley carved by floodwaters, until it wasn’t large enough to hold them all. Floodwaters followed a fracture in the basalt bedrock to the nearby Snake River forever abandoning its former channel.” The Snake River flows into the Columbia River.

Today it is a puny trickle compared to the 8-mile-wide stream of water that roared down the canyon 50-65 miles per hour during a large outburst flood from Glacial Lake Missoula.” (Adapted from Washington Rocks!)

It has now been universally established that cataclysmic Ice Age Floods swept across the Northwest. First, glacial ice lobes advancing from Canada formed an ice dam. With drainage blocked, enormous lakes formed: Glacial Lake Columbia and Glacial Lake Missoula. With the ice dam’s sudden collapse, a towering mass of water and ice over 2000-feet-deep would burst forth across the Columbia Basin at speeds up to 75 miles per hour emptying the lake within two or three days. Finally, the thundering torrent of water, icebergs, and mud raged across eastern Washington, taking the path of least resistance, on its way to the sea. (Credit: “Ice Age Floods of the Pacific Northwest” Eastern Washington Vacation & Travel Planner, Grant County Tourism Commission, 2020)

Grand Coulee Dam: The concrete structure of Grand Coulee Dam is one of the largest concrete structures in the world and contains nearly 12 million cubic yards of concrete. That’s enough concrete to build a 4-foot wide sidewalk around the world at the equator twice.

Grand Coulee Dam is relatively insignificant in comparison to the former ice dam that existed here damming the river and forming Lake Columbia.

East of here, the ice dam holding in Glacial Lake Missoula collapsed and sent catastrophic flood waters through the Grand Coulee.

Steamboat Rock: A 900-foot-tall monolith of basalt in the Upper Grand Coulee was named Steamboat Rock by early settlers when the coulee was dry! Banks Lake was formed due to the construction of Dry Falls Dam at Coulee City, and the rock now actually looks like a huge ship on water.

Dry Falls: Standing atop the sheer cliffs at Dry Falls, the signboards say one is standing in the pathway of some of the largest floods ever known and that this once was the site of the world’s greatest waterfall, over 3 1/2 miles long and 350 feet high! With the end of the Ice Age, floodwaters no longer swept through Grand Coulee, leaving the waterfall high and dry.

The Waterville Plateau is elevated hundreds of feet above the Grand Coulee. The northern half of the plateau was covered by a continental ice sheet during the ice age. The basaltic bedrock is covered with a layer of glacial sediment that supports agriculture.

Gingko Petrified Forest State Park: Ice Age floods stripped away surface material exposing petrified logs of semi-tropical trees that had previously been covered by molten lava.

Frenchman Coulee: “Water pouring out of Grand Coulee and other flood channels quickly filled the nearby Quincy Basin, and water escaped through three outlets, the southernmost which is Frenchman Coulee. The ravaging floodwater spilled into the Columbia River valley far below and formed a group of waterfalls that receded upstream to form Frenchman Coulee. The vertical canyon walls in the main coulee expose layer upon layer of Columbia River Basalt.” (Washington Rocks, page 48)

What Is Columnar Basalt? “The lower part of a thick lava flow is well insulated from the cooling effects of the atmosphere and cools very slowly compared to the upper part of the flow. The slowly cooling lava changes from a molten liquid into a very hot, mushy solid. Further cooling starting at the base of the flow caused the still hot, but now brittle, lava rock to contract and form regularly spaced contraction centers and radiating cracks that tend toward six-sided polygons.” (Washington Rocks! page 48)

Wallula Gap: When Glacial Lake Missoula drained hundreds of cubic miles of floodwater across eastern Washington, all routes led to the Columbia River and through a 1-mile-wide gorge about 6 miles north of Oregon named Wallula Gap. When the angry rushing waters reached this bottleneck, the waters slowed down and backed up to form a temporary lake, Lake Lewis, which required a week or more to slowly drain.

As we travel home from east to west down the Columbia River take notice of the changing landscape in the following series of photos.

Interested in Additional Information?

In 2009 Congress passed legislation authorizing an Ice Age Floods Trail to be managed by the National Park Service. The trail will consist of a four-state system of marked highway routes featuring significant landforms created by the floods. Visit the Webpage for the Ice Age Flood National Geologic Trail.

Ice Age Floods Institute webpage

YouTube: Is Genesis History? The Full Movie. There are two science paradigms: one requiring billions of years and one much less. Fascinating explanations by PhDs that believe in a young earth.

YouTube: Nick on the Rocks and Nick at Home series by Nick Zentner, a geology professor at Central Washington University in Ellensburg, Washington. His storytelling makes geology interesting and entertaining.

Credits: Much of the information I’ve shared in this post is taken from the signboards at the parks we visited. Thank you Washington State Parks.

Excerpts quoted from Washington Rocks! A Guide to Geologic Sites in the Evergreen State by Kiver, Pritchard and Orndorff. (Other titles include: Arizona Rocks! California Rocks! and Ohio Rocks!)

Links to related posts: Oregon: King of the Roads, Portland and Beyond, Eagle Creek Fire: One Year Anniversary, Day Trip to Stonehenge, “A Sight So Nobly Grand” in Oregon, Traveling the Great Glen Way

Next time, Meet You in the Morning will share The Cost of Travel: Eastern Washington Road Trip as well as additional photos of historic sites.

It is ironic that due to COVID-19, all travel plans to intriguing places abroad were canceled and people the world-over had to vacation close to home thereby discovering – or rediscovering – amazing sites in the back yards of their own countries!

Happy Travels wherever they may be! Thanks for following along!