The Cataclysmic Floods That Make Northwest Wines Unique
While on a vineyard tour in Oregon’s Willamette Valley, I asked about a huge boulder protruding from a hillside. “Oh, that,” said the vineyard manager. “It’s from Montana, and we didn’t drive it here on a truck”.
He went on to explain how massive basalt lava flows dating back some 15-20 million years gushed through the Pacific Northwest, stretching from Boise, Idaho all the way west to the Pacific Ocean, carving out what today is the Columbia Gorge and Oregon’s Willamette Valley. But then the melting glaciers of the last ice age (around 15,000 years ago) burst an enormous ice dam in Missoula, Montana, unleashing the biggest flood in the earth’s history. Imagine a wall of water 2,000 feet high, raging west through the Columbia Gorge and south as far as Eugene, Oregon several times over the course of 2,000 years.
Staggering, yes. But what does that have to do with wine?
Well, each flood, and the winds and volcanic ash that followed, carried heroic quantities of sand, stone and gravel. This formed the foundation of the topsoils that cover this land today. You can have markedly different soils in each of the Northwest growing regions—like Walla Walla and the Wahluke Slope in Washington, the Willamette Valley in Oregon, and the Columbia Gorge with vineyards in both states—as deposits from various floods can differ greatly. Soil types can vary widely within even a single vineyard, especially those on hillsides with a broad elevation range, all driven by the bounty of each violent event.
Some of the soils are volcanic in origin, and resultant wines tend toward red fruit characteristics and higher acidity. Others are ocean sediments that rose out of the Pacific muds, often leading to flavors of darker fruits like blackberries, with lower acid levels. I like wines made from each soil type—sometimes on their own, sometimes blended for complexity.
This phenomenon is like no other in the world, and enabled a virtual kaleidoscope of wines from Washington and Oregon. So when a winery in the Northwest speaks of expressing a unique sense of place, you can see that you’re in for a wine with an especially dramatic heritage.