The Dundee Hills AVA is an American Viticultural Area located in Yamhill County, Oregon. It is entirely contained within the Willamette Valley AVA, and is approximately 28 mi southwest of Portland, near the towns of Dundee and Dayton. The area is 6940 acre in total size, with 1300 acre planted with grapes. The Dundee Hills are a north-south oriented line of hills on the western side of the Willamette River valley. The soil is red in color, rich in iron, relatively infertile, making it suitable for grape cultivation. The region gets 30 in to 45 in of rainfall per year. The Chehalem Mountains to the north protect the region from the cool breezes that enter Willamette Valley from the Columbia Gorge. Over 25 wineries and independent vineyards in this region produce over 44,000 cases of wine. The Dundee Hills has been a grape growing region since 1966, when David Lett established Eyrie Vineyards, planting Pinot noir and Pinot Gris. In 1975, Dick Erath and C. Calvert Knudsen formed Knudsen Erath Winery, the first commercial winery to open in the Dundee Hills.