Willamette Valley AVA
Willamette is known for it Pinot Noir and Pinot Gris. Centered on the Willamette River and stretching south from Portland to Cottage Grove, Just south of Eugene. It is the largest and best known of the AVAs in Oregon, and has most of the states wineries. The interesting thing is that so many foreigner that have been well school for centuries in the fine art of growing and making Pinot Noir, have seen it fit to heavily invest in Willamette Valley. Many parts of the appellation have a distinct red soil with a heavy iron deposit in it. These are considered to be an important element in the development of structure and the body in Pinot Noir wines.The valley an be described as a series of hills and valleys providing south and east facing slops of clay and loam soils, providing excellent sun, airflow and drainage, creating great micro climates. In fact there are so many micro climates that have led to the establishment of six sub-appellations.
Map from The guild of Sommelier and info from Exploring Wines