Terroir
The Walla Walla Valley’s remarkable geological history has helped to shape a highly complex and varied terroir. The story begins 15 million years ago when the region experienced a series of colossal lava flows. This lava slowly cooled and eventually hardened into the basalt bedrock that covers much of eastern Washington and northeastern Oregon. Between 15,000 and 12,000 years ago – just yesterday in geological time – the Walla Walla Valley and the surrounding areas were inundated by cataclysmic floods. The floods were the result of glaciers moving south from Canada that stopped at the Clark Fork River in the Idaho Panhandle. This gigantic piece of ice formed a natural dam which created glacial Lake Missoula. The water behind the glacial dam slowly gathered until the volume was sufficient to float the ice dam and allow the huge reservoir of water that had built up to gush out and flow southward. This process repeated itself many times over this three thousand year period.
These floods deposited much of the well-drained sand and silt that today forms the soil of the Walla Walla Valley American Viticultural Area (AVA). These flood sediments are rich in minerals such as quartz and mica that were derived from granite bedrock hundreds of miles away. Even though the Missoula floods only reached elevations of 1,200 feet, winds following the floods swept flood-deposited silts known as loess onto the surrounding hills. After the floods, ash derived from the eruptions of Cascade Range volcanoes was deposited throughout the region adding even more complexity to the Valley’s soil.
In addition to the eclectic combination of soils that coat the Valley, the Walla Walla Valley AVA’s climate creates optimal conditions for viticulture. The Valley’s arid climate ensures that viticulturists are able to precisely control the amount of water given to grapes with the help of irrigation techniques. Located on latitude 46°, the Valley straddles the line between the Burgundy and Bordeaux regions of France. The long hot summer days and short cool nights around latitude 46° produces a perfect balance of sugars and acidity in the grapes. Additionally, this high latitude means that once autumn arrives the weather cools quickly and the hours of daily sunshine diminishes rapidly. As a result, grapes are able to remain on the vine weeks after they must be harvested in most other regions. This extra time on the vine allows the flavors within each grape to intensify and gain even more layers of subtlety.
The Walla Walla Valley AVA has a truly unique terroir. The influences of a dramatic geological history and an ideal climate have combined to set the stage for our Valley’s winemakers to produce consistently world-class wines.