There are currently 6 AVA's in Oregon, with many more seeking approval. Willamette Valley, for example, has several sub-regions that could be classified as AVA's. The interesting paradox in Willamette though, is that many winemakers do not want to give up the Willamette Valley AVA on their bottles, because they fear they would lose the prestige Willamette has come to represent. Columbia Valley and Walla Walla are two of the Oregon AVA's, but they mostly lie within Washington state, and while there grapes grown there, there are no actual Oregon wineries in the AVA's.
Willamette is Oregon's primary wine producing area. It runs North to South and lies about 50 miles east of the Pacific, which gives the area a maritime climate. Most of the vineyards are planted on the sides of the hills on the western side of the Valley. Willamettte Valley features Red Jory Clay and Willakenzie Alluvial Soil. The 4 sub-regions of the valley, all of which could be considered as a sub-AVA, are the Red Hills of Dundee, Eola Hills, South Salem Hills, and the area just to the west of Eugene.
Umpqua Valley is just south of Willamette. The Valley has many hillsides that offer drainage from the rivers in the area. It is drier and warmer than Willamette, and allows many different grapes to be grown, including Pinot Noir, Cabernet Sauvignon, Sauvignon Blanc, and Riesling.
The Rogue Valley is the longest standing wine area in Oregon. It has two distinct climactic areas. In the western area, the Illinois Valley, the Pacific Ocean's proximity exerts a great deal of cooling influence, and Pinot Noir is most common. South of the Valley, the Rogue River sub-region is more sheltered from the Ocean, and the warmer drier climate is better for Bourdeaux style varietals, as well as Chardonnay.
Applegate Valley is Oregon's newest AVA. It separates the Rogue Valley into North and South. It has deep soils that drain very well, and has warm days and cool nights. The best wines from this area are intense full-bodied reds including Merlot, Syrah, Zinfandel, Cabernet Franc, and Cabernet Sauvignon.