High Quality Content by WIKIPEDIA articles! The Willamette Valley AVA (pronounced /w??læm?t/ wi-LAM-it), is an American Viticultural Area which lies in the Willamette Valley of Oregon. THe AVA is the wine growing region which encompasses the drainage basin of the Willamette River. IT stretches from the Columbia River in the north to just south of Eugene in the south, where the Willamette Valley ends; and from the Oregon Coast Range in the west to the Cascade Mountains in the east. AT 5,200 square miles (13,500 km2), it is the largest AVA in the state, and contains most of the state's wineries; approximately 200 as of 2006.