Where it is
Most vineyards are in the Columbia Valley in the east of the state, which includes the Yakima Valley, Walla Walla Valley, Red Mountain and Horse Heaven Hills AVAs. Puget Sound is cooler and much smaller.
Land and climate
The Cascade Mountains block rain, so vineyards are irrigated. Summer days are long and hot, and nights are cool. Winter freezes can damage vines.
Grapes and wines
Cabernet Sauvignon, Merlot and Syrah are the main reds, and Riesling and Chardonnay the main whites. Chateau Ste. Michelle is the biggest winery.