(Wines&Vines) - It’s official: the Rocks District of Milton-Freewater AVA has been designated a subappellation of the Walla Walla Valley AVA, bringing joy to vintners in Oregon and Washington.

“This is a golden thread in the tapestry of the Walla Walla Valley,” said Rich Funk, winemaker at Saviah Cellars just north of the appellation, who worked with Steve Robertson and six other growers to petition the federal government to establish the new AVA. “This is as much about the Walla Walla Valley as where the next 10 years will lead us. It’s just a wonderful way for us to tell our story.”

The Walla Walla Valley AVA includes vineyards on both sides of the Oregon-Washington state border, which runs east-west a few miles south of the city of Walla Walla, Wash. But the new Rocks District of Milton Freewater is strictly in Oregon and named for the small town of Milton-Freewater. Wineries have long sourced grapes from the new appellation (effective Feb. 9), but now some of them have the opportunity to identify the source of those grapes as a rock-covered stretch of floodplain along the southern edge of the valley.

According to the petition developed by geologist Kevin Pogue, the Rocks District encompasses approximately 3,770 acres that sit on an alluvial fan where the Walla Walla River exits the foothills of the Blue Mountains. Situated between 850 and 1,000 feet above sea level, the AVA is less susceptible to winter damage than other parts of the Walla Walla Valley AVA.

The Rocks

The distinctive basalt cobblestones that litter the soil give the district its name. The rocks ensure good drainage, encouraging vine roots to reach for water, and also absorb solar radiation that’s released into the canopy above, promoting growth in the spring and ripening after véraison. The growing season is approximately 197 days.

The distinctive qualities of the area were championed early on by producers such as Christophe Baron of Cayuse Vineyards, who planted his ground-breaking Cailloux Vineyard in 1996. It was the first planting in the AVA and impressed people both with its daring and its results.