No grape variety is as reflective of climatic and site differences as Pinot noir. That is why it demands a cool climate to thrive and why small distance differences in the valley often yield wines of distinctively different character. General attributes that make the Willamette Valley suitable for cool climate grape growing include the protection afforded by the Cascade Mountains to the east, Coast Range mountains to the west and a series of lower hill chains to the extreme north of the valley. Almost all grape growing is done on lower hillsides, avoiding deeply fertile alluvial soils and cooler hilltop mesoclimates.

It is on these hillsides that Pinot noir uniqueness is found and where apparent families of wines urge distinctive American Viticultural Area identification. In 2002, a collaborative action of vineyards and wineries delineated and submitted to the TTB petitions to divide much of the northern part of the large Willamette Valley AVA into six more specific AVAs: Chehalem Mountains, Dundee Hills, Eola-Amity Hills, McMinnville, Ribbon Ridge, and Yamhill-Carlton. The Van Duzer Corridor AVA went into effect in January 2019, the Tualatin Hills and Laurelwood District AVAs were approved in June 2020, and the Lower Long Tom AVA was established in November 2021. Mount Pisgah, Polk County, Oregon was established in June 2022.