100 years ago, J Harlen Bretz figured out Eastern Washington’s geological backstory

On a map, the Channeled Scablands look like a couple of melting gray jellyfish draped across Eastern Washington.

The jellyfish have fat and skinny tentacles that flow southwest from Spokane, wrapping around islands of wheat fields. The tentacles are geological scars, zones where water ripped away the topsoil thousands of years ago and left behind hard basalt. Across 15,000 square miles, between Spokane, Quincy and Walla Walla, the landscape is teeming with desolate cliffs, buttes and canyons.

Nothing like the Channeled Scablands exists anywhere else on the planet. But geologists didn’t figure out how the region formed until 100 years ago, when J Harlen Bretz published his second paper on the region in late 1923.

Bretz began exploring the Scablands in 1922 as a fedora-wearing, pipe-smoking 40-year-old. After two summers spent hiking all over Eastern Washington, the University of Chicago geology professor theorized that the Scablands were formed by cataclysmic floods.

“The largest flood in the world that ever happened,” Bretz biographer John Soennichsen said in an interview.

Bretz argued that only a flood of nearly incomprehensible proportions – now thought to contain 10 times as much water as all of the world’s rivers combined – could have carved out the Scablands. Plowing through hills, gouging out canyons and carrying car-sized boulders hundreds of miles would have required enormous amounts of water, Bretz reasoned, and that water must have hurtled over the ground in a matter of days or weeks.

In the years after he published his 1923 Channeled Scablands paper, Bretz faced skepticism and ridicule from his fellow geologists. They saw him as a renegade.

“Bretz became a pariah to other members of the geologic community who preferred to envision scenarios of slow, gradual change over hundreds of thousands of years, not a short-lived flood that smacked of Biblical catastrophe,” Soennichsen wrote in his Channeled Scablands guide book.

But now, a century after Bretz and his students drove throughout the Channeled Scablands in a Model T, mainstream geologists agree he was right. Eastern Washington owes its unique geology to Ice Age floods that dwarfed all other floods known to science.

Bretz’s discovery, that cataclysmic flooding rapidly transformed an entire region, had a significant impact on the field of geology. His findings on the Scablands changed what geologists viewed as possible.

In the 1920s, mainstream geologists rigidly believed in uniformitarianism – the idea that geological features could only form over thousands or millions of years. They viewed catastrophism as unscientific.

But by the 1970s, geologists had accepted catastrophism as legitimate. Bretz’s work allowed for new ways of thinking and paved the way for new discoveries. For instance, the idea of a meteor crashing into Mexico and indirectly wiping out the dinosaurs now seems perfectly plausible.

“Changing the paradigm took a long time,” Eastern Washington University geology professor Chad Pritchard said.

Piecing together the clues

Bretz, who grew up in Michigan, became interested in the Channeled Scablands after seeing some odd features on a map during his time as a Seattle high school teacher. He retained his fascination for Washington geology even after leaving the state and taking a job at the University of Chicago.

When Bretz and his students began trekking across Eastern Washington in 1922, the Channeled Scablands had been little studied. That lack of study was due in part to the region’s remoteness. Geologists in Bretz’s day were also less inclined to do field work.

“They didn’t care enough to go out and research,” Soennichsen said.

Before Bretz and his students began walking the Channeled Scablands and piecing together the backstory, geologists believed that glacial streams had gradually formed the landscape over thousands or millions of years.

But once Bretz investigated the land on foot, he realized glacial streams couldn’t be the culprit. Standard glacial meltwaters wouldn’t have been powerful enough to form the Scablands.

Bretz found out-of-place boulders high on canyon walls, carried there from hundreds of miles away. He saw huge gravel bars and water lines high up on hills. In some areas, chunks of basalt bedrock had been torn away.

The evidence suggested that vast quantities of water had passed through swiftly. The gradual erosion theory, which explains how the Colorado River carved out the Grand Canyon over millions of years, didn’t fit.

No common geological theories of the 1920s seemed to fit.

Geologists now know catastrophic floods have formed other features around the world – the English Channel was dug out by a flood, for instance. But Bretz didn’t know that at the time and had no models to pull from.

“To understand the Scablands, you have to throw away the textbooks,” said Vic Baker, a University of Arizona geology professor who knew Bretz.

By the fall of 1923, Bretz was confident floods formed the Channeled Scablands, even if he didn’t know the water’s source.

Most modern geologists believe the water came from Glacial Lake Missoula in western Montana, which was roughly half the size of Lake Michigan.

Glacial Lake Missoula was bounded, in part, by a glacier 2,000 feet high. That ice dam, in North Idaho’s Clark Fork Valley, prevented the lake from emptying into the panhandle.

But for about 2,000 years, around 14,000 years ago, the dam broke and reformed dozens of times.

When the dam failed, Glacial Lake Missoula poured westward. Tendrils of floodwater thundered across much of Eastern Washington before reconvening near Walla Walla and following the Columbia River to the Pacific Ocean.

Baker said it’s difficult to fathom the power of the floods.

“They moved boulders tens of meters in diameter, and the boulders were moved in suspension,” he said.

The sound of the flood was 10,000 times louder than the crash of Niagara Falls. The muddy waters moved at upwards of 50 mph.

“It was just this huge, dense flow of water, and debris, and trees, and Columbia mammoths, and ice blocks, and things just rushing through very, very fast,” Pritchard said.

Today, thanks to Bretz, scientists think of the Scablands as a unique geological marvel. Bretz is well-known and often mentioned as one of the most important geologists of the 20th century. He stood by his theory for decades, despite being labeled a radical by his peers.

He lived long enough to say “I told you so.” Bretz received the Penrose Medal in 1979, the Geological Society of America’s highest award. He died two years later at 98.