Washington Wine Country is becoming well known and popular with wine enthusiasts.  While the region defined here has the highest concentration of wineries, there are more spread out throughout the state including most regions.

Washington is comprised of two major climate zones that are split by the Cascade Mountain range.  The west side of the state receives more rainfall from the coastal waters, an the east side receives much less rain as the Cascades hold back the moist ocean air.

Eastern Washington is where approximately 98 percent of Washington wine grapes are grown.  The US Government has designated  five major viticulture appellations defining specific geographic regions of the state.  Red Mountain, Yakima Valley, and Walla Walla Valley are located in the large Columbia Valley appellation.  Western Washington contains the Puget Sound appellation.

There are also areas outside the official viticulture appellations that are awaiting official sanction, including the new Columbia Cascade which includes part of Grant County, Douglas, Chelan, and Okanogan Counties.

Itineraries that include wine regions are: "White Wine and White Water", "Northern Exposure", "Higher and Dryer"
 

For more research, please also see Washington Wine Commission site.