Physiographic Cusp

Courtesy of Regional Landscapes of The U.S. & Canada,
Ch.2, pg 19.

Physio Region

Since the Dalles is technically on the Columbia Basin, that very basin shares two physiographic regions: Pacific Mountains & Valleys (west) & Intermontaine Basins & Plateaus (east). Judging from just looking at the map, it is definitely hard to pinpoint what physiographic region The Dalles is a part of.

I had to bump my google searching up a notch in order to get a clearer answer. 

Thank you OSU (source).

 It is a narrow province that runs north-south. It neighbors the Cascade Mountains as well. Physioregion-wise, The Dalles leans towards the Pacific Mountain & Valley region. According to this OSU description of Oregon's provinces, there are foothills and mountain slopes running east-west, coming from basalt cliff canyons from the Cascades, draining into Deschutes  and Columbia rivers. 

Soils

 The eastern slopes of Mount Hood & the Cascades have influenced the soil types in The Dalles: aeolian silts, volcanic ash, andesitic, basaltic,  sedimentary colluviums,  glacial outwash (OSU source). According to Chapter 2's Regional Landscapes of The U.S. & Canada, this map demonstrates the soil territories throughout the states.

Mollisols are the soil type territory for North-central The Dalles. According to the chapter, mollisols are one of the most fertile soils there is. The texture is thick, dark, and very rich in nutrients. This explains very well the cultivation of cherries and peaches in the fields of The Dalles!

I'm quite intrigued over the fact that The Dalles neighbors different elements of the region next to theirs. The fact that it runs north-south, shares different geographic territories, Cascades in the south, Columbia grassland basin to the north. I'm excited to learn more about how this little piece of "regional cusp", as I have labeled, transitions within those 100 miles.

Next post: Climate & Vegetation.

[Research curiosity alert: Deschutes, Columbia River systems, cherries!]