|Scott Burns at 2011 PNW NAGT Field Conference in Malheur Count, Oregon|
|Washington Viticulture Areas|
The other misconception I had had was that the reason Eastern Washington and Eastern Oregon were prime wine growing regions was because of the volcanic soils. While it is true that many of the Oregon wines are from volcanic soils, that is mostly in the cooler/rainier western part of the state where the lace of soil nutrients can be the stress that promotes fruit growth. Here in the eastern part, it is more likely to be water (or the lack thereof) that stresses the vine into producing grapes, thus most of the vineyards in this area are in richer silty soils deposited by the Missoula Floods.
Most of the main channel flooding occurred north and west of here, but the natural constriction of the Columbia River Gorge caused water to backflow up the John Day and Umatilla drainages (Lake Condon). A similar lake (Lake Lewis) was formed by flood waters backing up the Walla Walla drainage due to the restriction at Wallula Gap.
|Missoula Flood transient Lakes created by topographic constrictions|
In all it was a good talk, it gave me more things to think about regarding the geology of the area, and learning more about terroir is a good reason to stop in some of the local wineries.