Washington Wines made in Walla Walla.

Bridging both Washington and Oregon, the Walla Walla Valley AVA ranges from 400 to 2000 feet in elevation, and receives between seven and 22 inches of rainfall depending on the area of the valley. This area is a regional agricultural hub that abounds with crisp apples, juicy strawberries, tender asparagus, sumptuous sweet onions, and nearly 3,000 acres of prime vineyards.

Encompassing nearly 11 million acres, Columbia Valley bridges the states of Washington and Oregon, and was established as an American Viticulture Area in 1981. Variety typicity and pure fruit aromas and flavors are the hallmarks of wine from the Columbia Valley. The relationship to the Missoula Floods, a series of cataclysmic events, defines the soil types of the vineyards in Washington. Most vineyards lie below the floodwaters with soils of loess—wind blown deposits of sand and silt—overlying gravel and slackwater sediment with basalt forming the bedrock. This provides a diversity of soil types that are well drained and ideal for viticulture. The Columbia Valley lies in the rain shadow of the Cascade Mountain range. The region has an arid and semi-arid, continental climate, receiving an average of 6–8 inches (15–20 cm) of precipitation annually. Irrigation is therefore required to grow vinifera grapes. This irrigation, along with consistently warm, dry temperatures during the growing season, provides growers with a large amount of control over grape development compared to many other regions of the world. This leads to minimal vintage variation and high-quality wines.

The smallest appellation in Washington State at 4,040 acres, Red Mountain is named after the reddish hue of cheatgrass in the spring. This is a hot AVA with 6 to 8 inches of average rainfall and the plantings are primarily red grapes. Red Mountain soil is made up of sandy loam and gravel with high alkalinity (high pH) and a rich calcium carbonate content. A lack of soil nutrients along with the high pH reduces the vigor of the vines, resulting in significantly smaller berry sizes compared to varietal norms. This, along with prevailing winds, leads to higher tannin levels in many of the wines compared to other regions.

The Horse Heaven Hills is 570,000 acres (230,671 ha) in size, with elevations ranging from 200 feet (61 m) above sea level along the Columbia River to 1,800 feet (549 m) at the northern boundary. Pressure differentials cause significant winds in the Horse Heaven Hills. These winds reduce canopy size and toughen grape skins, as well as protect against mold and rot. The nearby Columbia River also has a moderating effect on temperatures, reducing the risk of early and late season frosts, which can be a problem in nearby areas. The area is among Washington’s warmer growing regions, allowing a wide variety of grapes to ripen successfully.

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. 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.

The Yakima Valley is one of Washington’s cooler growing regions. For this reason, white grape plantings outnumber red grape plantings. Yakima Valley Chardonnays display a variety of aromas and flavors depending on the relative warmth of the vineyard site. Cooler sites are notable for fresh green apple and warmer sites for stone fruit and tropical fruit. While a cooler region compared to its peers, the Yakima Valley also includes the Red Mountain appellation, which is consistently one of Washington’s warmest growing regions. There is, therefore, considerable diversity across sites. The Yakima Valley wholly contains the sub-appellations Rattlesnake Hills, Red Mountain, and Snipes Mountain.