Oregon’s Wine Geography
Because of its geographic diversity, one cannot easily generalize about Oregon wine. The state’s four broad growing regions are more varied in climate and topography than those of Washington or Idaho. Though often thought of only as pinot noir country, Oregon’s mix of viticulture climates makes for the most successfully varied winegrowing areas in the Northwest.
Like its neighbor to the north, Oregon is dramatically divided west to east by the two-mile high backbone of the Cascade Range, and two-thirds of the state lies east of these mountains as vast, sparsley populated, high-elevation desert. But unlike Washington, the great bulk of Oregon’s vineyards and wine production occur in the western third of the state. And unlike any other part of the Northwest, Oregon is best known for its cool-climate wine countries.
Standing the the middle of a Willamette Valley vineyard under a sweltering summer sun, it can be difficult to think of this area as cool—but to a grape vine, it is. Spreading south from the urban mass of Portland to just below Eugene, the Willamette Valley AVA is home to over 80% of the state’s vineyards and wineries. Vineyards are primarily planted on the eastern slopes of the valley’s west side at elevations between 200- and 900-ft. with either volcanic or marine sedimentary soils. Only about 40 to 60 miles from the Pacific Ocean, much of the Willamette Valley experiences marine-influenced temperate weather that makes it the most successful cool-climate wine country in the Northwest.
Vineyards in the valley experience typical growing degree days ranging from 1825 to 2100 with a median of 1946. By comparison, Napa Valley averages 2880 and vineyard elevations in Washington’s Columbia Valley have a median close to 2400. Protected from summer storms by the Coast Range, but still affected by its proximity to cooling marine air, the foothill vineyards experience dry and warm summers and mild, wet winters. Vineyards here achieve just enough growing heat for vinifera.
It was precisely this wine-growing marginality that most appealed to Oregon’s earliest modern wine pioneers. They believed that for some noble varieties a cool climate was more advantageous than a warm one. They felt the best varietal expression of a fruit was achieved when its natural ripening cycle coincided with the end of the climactic growing season. The ripening pattern of pinot noir, they observed, matched the climate of the Willamette Valley: just when the grape’s ripening sugars, acids, and flavors came into balance in the Willamette Valley, was also just when the weather turned from warm and dry to cool and wet—very late September and early October. In warmer areas, they felt, pinot noir (and other early ripening varieties) was rushed to ripening by excessive heat, leading to harvesting less-than-balanced fruit in early September and sometimes August.
But if the great promise of Oregon’s cool-climate growing places is achieving the best flavor characteristics in early ripening wine grapes, then the great uncertainty is that vintage variation in such a marginal growing region can be extreme and unpredictable. Depending on the weather during the last critical weeks of ripening, a vinatge can go from seeming greatness to mere mediocrity in a matter of days. Today, with long experience in managing unpredictable vintages, Willamette Valley growers have learned how to adjust, almost on a day to day basis, to conditions in order to maximize wine quality depending on what each year delivers.
Oregon is about more than pinot noir—and more than the Willamette Valley. Deep into southern Oregon, throughout much of the northern border area, and into the eastern parts of the state lie Oregon’s warm-climate growing regions producing a wider range of wines (though in lesser quantities) than is possible in the Willamette Valley. In fact, the modern Oregon wine industry got its start in southern Oregon when Richard Sommer planted a vineyard in 1961 outside Roseburg—including the first pinot noir planted in the state.
Average growing temperatures in the Southern Oregon AVA (an umbrella appellation that encompasses a number of smaller AVA—see the map) are 300 500 growing degree days higher than in the Willamette Valley (generally between 2300 and 2800), and individual sites have reported growing degree days of up to 3000. Like the Willamette Valley the appellation is protected from ocean air by the Coast Range in the north and the Klamath Mountains in the south, but here the geology is very different, more mountainous, higher elevation, and with varied granitic and glacially-derived soils. Southern Oregon is also considerably drier during the growing season.
The Northern Border region is also primarily (though not exclusively) a warm-climate area and encompasses the Oregon portions of the Columbia Gorge, Columbia Valley, and Walla Walla Valley AVAs. The topography of the Northern Border area is complex and varied, and subject to constant winds thanks to its proximity to the Columbia River. Sites vary from green slopes tucked into lush agricultural valleys to harsh, almost barren hilltops and river benches.
While growing degree days at some sites can be as high as 2600, there are others as low as 1500. The median growing degree days in in the Columbia Gorge AVA is 1665. While
the Northern Border might be more accurately labelled a transitional wine country between cool and warm growing climates, the majority of vineyards fall closer to the warm climate category
Walla Walla Valley
The Walla Walla Valley is part of the Northern Border, but merits a special note. Though the Walla Walla Valley is almost exclusively associated in people’s minds with Washington, a significant portion of its acreage lies in Oregon. In fact, some of the AVA’s best-known Washington wineries have estate vineyards in Oregon—including L’Ecole No. 41, Figgins Family Wine Estates, Buty, and Waters, and one of the appellation’s most famous grape source, Seven Hills Vineyard, is in Oregon. Even Cayuse, one of Washington state’s most famous boutique labels, has its winery and estate vineyards in Oregon.
Currently, the only appellation in the eastern reaches of Oregon is the western portion of the Snake River Valley AVA. This huge territory is has its vineyard and winery population almost exclusively located in Idaho, with only a few vines planted so far in Oregon. This desolate, high desert country is sparsely populated and viticulturally unexploited, but it shares many of the same climate and soil conditions of eastern Washington. No doubt in future years this area will see additional vineyard development and is likely to grow in importance to the Northwest’s wine production.