red wine splash
Image: Erik Skaar

THE POPLAR TREES lining the side of the property drooped in the sweltering sun as Jim Holmes stood up from the pile of wood where he’d been sitting for the past hour. He ambled over to a row of neatly crucified vines, stopped, and crouched on one knee. These were the celebrated Ciel du Cheval vines—“horse heaven” in French, an homage to the nearby Horse Heaven Hills, once the favored grazing spot of now-extinct wild stallions. He scooped up some dirt.

“Hold out your hand,” he said.

I opened my palm. The gray silt felt at once light and substantial, like talcum powder. Tiny sparkly specks stuck to my skin, glistening in the sunshine. “That’s mica,” Holmes explained, “from the Rockies. It came with the floods.”

How soil came here from hundreds of miles away—and created some of the most fecund land in the West—was a mystery that consumed geologists for centuries. The answer holds the key not just to the dirt here, but also to why Red Mountain produces wines of highly celebrated terroir, a French term that refers to the characteristics (climate, soil, farming techniques) that link a wine to the place where the grapes grew. Red Mountain’s renowned terroir has attracted distinguished winemakers and drinkers from around the world and grapes grown there are among the most prized and expensive in the state. And it all happened because of a flood.

Or rather, floods. Near the end of the last glacial period, around 15,000 years ago, a beast of an ice lake submerged much of western Montana: 500 cubic miles of water—about as much as Lake Erie and Lake Ontario combined—reaching depths of 2,000 feet. Near the top of what’s now the Idaho Panhandle, a thick sheet of ice dammed the lake, preventing it from spilling westward…except when it didn’t. Over a period of about 3,000 years, the frozen dam ruptured under the pressure of the water more than a dozen times, and a thrust of liquid muscle advanced on Eastern Washington and parts of Oregon en route to the Pacific Ocean.

These were floods of unimaginable power, fierce enough to scoop up many-­ton boulders and send them crashing into one another with such violence that they disgorged debris in thick, dirty plumes. Giant woolly mammoths were swept away in a second. In their path of destruction, the waters of Glacial Lake Missoula ripped up the earth’s surface, sculpting massive potholes, buttes, and the gouged-out canyons known as coulees.

Along this crash course to the Pacific Ocean, the floods encountered Red Mountain, a cheatgrass-covered elevation just east of what is now Benton City, Washington, in the southeast corner of the state. At just 1,247 feet, it isn’t much of a mountain. It’s a ridge, really—an uplifted fold in the earth created by plate movement. But it was tall enough to form an eddy in the flood, a swirling effect that slowed the water down, causing it to release rock and debris picked up along the way. Over time, Red Mountain soil became a time capsule of displaced earth, an elemental hodgepodge that told the geological story of Lake Missoula’s violent journeys.

At Ciel du Cheval, I asked Holmes if the floods, and the soil they created, were the reason wines from Red Mountain taste better than other wines. He frowned. “Better or worse, don’t worry about that. The thing is we’re different. We’re fundamentally different.”

The night before, a stranger had requested, of me, the same information I sought from Holmes. I was loitering on the lawn during a wine-tasting party at Col Solare Winery, the deep-pocketed winemaking collaboration between Chateau Ste. Michelle and Marchesi Antinori, a famous Tuscan whose family has been in the business since the 14th century. Beyond the long stone wall that guards the winery like it’s some medieval castle, a couple of men were readying a striped hot air balloon for flight and I watched as the balloon part—the envelope, they call it—started to fill with air. A man approached to have a look, too, and we got to talking. So what made the grapes so great here? he’d asked, savoring the last sip of inky syrah in his glass. Standing there, taking in the rows of leafy vines and the dusty ground beneath them, the lingering peaches-and-clay sunset, and the stout Horse Heaven Hills beyond, I should have already known it was the wrong question.

A GEOLOGIST NAMED J Harlen Bretz uncovered the secret of Red Mountain soil. In the early days of the twentieth century, Bretz taught for a stint at the University of Washington before returning to the University of Chicago to make his career. By then he was already obsessed with the place that was the subject of his PhD dissertation: a geological anomaly that would consume his professional life, for better or worse, for the next half century.

Bretz was the first to refer to the area around the Grand Coulee, where massive erosion had bruised and battered the native basalt deposits, as “the channeled scablands.” Something of an erosion expert, Bretz could not accept the prevailing theory that these deep fissures and ripples had happened gradually—they just didn’t fit the mold. The idea nagged at him. Even after he’d settled back in to Illinois life, every summer for eight years starting in 1920, Bretz packed up his crew—wife, two kids, a collie, and a student or two—and drove west to explore the scablands.

The students must have been robust: Bretz was brash and intellectually demanding. He was also a prankster. An amateur winemaker, he kept a wine cellar, hidden Scooby Doo–style behind a bookcase. He’d bring his acolytes into his home and invite them to try to find the secret cellar. When they did he’d lock them inside, leaving them there to figure out how to escape. Despite his antics they came along, scouring the desert for answers with their pipe-smoking professor, who wore a metal construction worker’s hat to protect his bald head from the sun.

In 1927 Bretz traveled east to formally present his scablands theory to colleagues at the all-important annual meeting of the Geological Society of Washington, DC. Bretz had arrived at the conclusion that a giant catastrophic flood, not gradual erosion, had scarred the area around Grand Coulee. The question was: Where had the water come from? Bretz didn’t know. And without that information, his theory, well, it held no water.

It wasn’t just that. Uniformitarianism, the prevailing idea behind geological study, dictated that things happened gradually over millions and millions of years. The theory that a massive flood had devastated the land in a single swoop (or even, as it turned out to be in this case, over three millennia­—a mere blip in geological time) struck Bretz’s colleagues as catastrophist. And being a catastrophist in the 1920s geological world was a bit like being a climate-change-denier today. They thought he was a kook.

Some of his colleagues and students supported him, and Bretz kept up with his work despite the general rejection of his peers. Then, in 1940 another geologist published evidence of ripple marks in western Montana, inadvertently lending credence to the flood theory. But not until the 1970s, when aerial photos showed convincing evidence of a flood path, did Bretz’s ideas earn general acceptance among geologists. Official redemption arrived in ’79, two years before his death, when Bretz received the field’s most respected medal, the Penrose. He was almost 100 years old and most of his critics were long dead, but it didn’t really matter. Bretz had secured his place among the heroes of geology, heralded for sticking to his guns in the face of mockery and shortsighted scorn from his contemporaries.