Winemaker Co Dinn takes us on a 360° spin of Washington’s wine valley formation from the top of Snipes Mountain overlooking Yakima AVA. Make sure to move your screen or click and drag to get the full 360° view!
Clip excerpt for the hearing impaired:
Amanda: We are in a rather hot spot, on the side of Snipes Mountain, and we’ve got an amazing view that way straight down the valley. Can you give us a rundown about the geology of Yakima and how it was formed, and why we have different rocky soils up here to what we have down there?
Co: Well, that’s a great question and we’ll start by saying right out south west you can see basalt rocks. And the basalt rock was the result of massive outpourings of molten lava 15 million years ago. And it all flowed out and solidified into basalt, and formed a flat plain. So everything that we see, is after the basalt came – after that initial flood of basalt. So, what happened? Why is it not all basalt? Well, various things, we had a river that came through, and it was flat, the ancestral Columbia (river). The current Columbia river does not go through here, but the ancestral one did and it laid down these layers of sand and river gravel that we see all around us here – at the top of Snipes Mountain. Well that begs the question, what’s river gravel doing on top of a hill? And so between the time the river flowed and now, there was tectonic activity that lifted, squeezed and formed this valley. So you can see in the distance to the south, that’s Horse Heaven Hills, there’s a very vast east running west ridge line. And we are on an east running west ridge, Snipes Mountain. To the north are the Rattlesnake Hills. And there’s an accordion-like series of east running west hills and we are standing on one of them. The gravel was uplifted during this activity and subsequently wind deposited loess (or sandy loam) was blown in and filled in the other soil, dirt and rocks and gravel and mud washed from the Cascade Mountains down the Yakima river and formed a flood plain in the valley floor. The soils in the valley floor are very deep and rich, and all kinds of crops are grown down there, mainly animal crops like hay, corn, and hops, and these are plants that are very cold hardy. They can survive cold winters, in the winter time the cold air settles. So we don’t plant grapes down the valley floor. First we want very poor soils so the grapes have to struggle and produce a small berry and low vigour grape vines, and it is also warmer up here on the hill side. In the winter it is 5 degrees F warmer than it is on the valley floor, just because of the elevation. We have a level of frost protection up here, we have more heat accumulation in the summer, and we have better soil for grape vines and better drainage for the roots. So everything about this hill is conducive to very high quality wine grape viticulture and everything about the lower part of the valley is great for cropping large quantities of commodity crops, which need this soil. So if you want to grow tons of hops or hay, you do it on the valley floor, if you want to good quality Syrah right up here on the hill tops!
Amanda: Thank you for explaining to us!