• The Wahluke Slope AVA near Mattawa is home to more than 20 vineyards and three wine production facilities, including the Milbrandt Family’s Wahluke Wine Company. Photo by Andrea Johnson.

The Wahluke Slope AVA

Red grape varieties are the stars of this isolated Grant County, Washington, wine region.

The Wahluke Slope, named after a Native American word for “watering place,” lies totally within Grant County, WA. The area is geographically isolated, bordered by the Columbia River, Saddle Mountains, and Hanford Reach National Monument.

As one of the warmest regions in the state, the Wahluke Slope is known primarily for red grape varieties, particularly Cabernet Sauvignon, Merlot, and Syrah. Wahluke Slope wines tend to be ripe and full-bodied with pure varietal fruit flavors.

Cabernets are notable for black cherry and cassis aromas and flavors. Merlots display red fruit, such as sweet cherries, red currants, and raspberries, along with chocolate. Syrahs tend to display dark fruit, such as blackberries and blueberries, although some also display abundant savory notes.

Named as an official Washington State appellation in 2006, the Wahluke Slope produces approximately 20 percent of the entire Washington State grape harvest each year. Gravelly, rocky soil, combined with a dry, warm climate, make Wahluke Slope one of the best places in Washington to grow wine grapes.

Located within the larger Columbia Valley AVA, the Wahluke Slope is home to 20 vineyards but just two wineries —  Fox Estate Winery and Ginkgo Forest Winery. Fox Estate Winery is located in Mattawa, WA. (509) 932-5818. Ginkgo Forest’s winery is also located in Mattawa. (509) 932-0082.

Jerry Fox and his family have been growing wine grapes on their Fox Estate Vineyard since the early 1980s. Ginkgo Forest Winery opened its winery tasting room in 2007; and now operates tasting rooms in Prosser and Tacoma, WA.

Also operating on the Slope are three crush facilities.  The Millbrandt Family’s Wahluke Wine Company located near Mattawa is a custom-crush facility where bulk wine is made for growers and other wineries; it is not open to the public, but Coventry Vale, another customer crush facility, operates a production facility in the far eastern part of the Slope.  It, too, is not open to the public, nor is the crush facility of Lost River Winery also operating on Wahluke Slope. Lost River does, however, have a wine cellar and tasting room in Winthrop, WA.

Grapes grown on the Wahluke Slope are used by wineries throughout Washington, most notably Chateau Ste Michelle, Columbia Crest, Desert Wind, Hogue Cellars, Northstar, Snoqualmie Vineyards, Three Rivers Winery, and dozens more.

The major distinguishing feature of the Wahluke Slope is its uniformity in aspect, soil type, and climate. The entire appellation lies on a broad, south-facing slope with a constant, gentle grade of less than 8%. This, along with the proximity to the Columbia River, helps minimize the risk of frost, which can affect other areas of the state.

The entire 81,000-acre appellation sits on a large alluvial fan, making the soils notably uniform over a large area. The topsoil is deep, wind-blown sand with a depth, on average, of more than 5 feet (150cm). This provides both ample drainage for vinifera vines and greater uniformity in plant vigor and ripening than seen in other areas of Washington.

Elevations vary between 425 feet by the Columbia River to 1,480 feet above sea level, though most vineyards lie below 1,000 feet. Precipitation averages less than 6 inches (15cm) annually. Irrigation is therefore required to grow vinifera grapes. Winds in the area lead to smaller leaf size and smaller grape clusters compared to other regions, concentrating the resulting wines.

While most vineyards on the Wahluke Slope have been planted in the last 15 years, vineyards in this area have already created wines with high accolades. Of note, Wine Enthusiast awarded a 100-point rating to a wine from this region and Wine Spectator named a wine made from Wahluke Slope fruit its Wine of the Year in 2009.

Vital Statistics

  • Established in 2006, Wahluke Slope is naturally bounded by the Columbia River to the west and south, by the Saddle Mountains on the north, and on the east by the Hanford Reach National Monument.
  • The Wahluke Slope AVA lies entirely within the established Columbia Valley appellation and is home to more than 20 vineyards and three wine production facilities.
  • The 81,000-acre region features approximately 8,491 acres of vineyards: nearly 15 percent of the total wine grape acreage in the state.
  • Top grape varieties: Merlot, Syrah, Cabernet Sauvignon, Riesling, Chardonnay, and Chenin Blanc.
  • Wahluke Slope has one of the driest, warmest climates in the state, allowing nearly complete control of vine vigor and ripening through irrigation.