I-84 – Oregon’s Necklace of Ecoregions

I-84 is a necklace worn by Oregon strung with ecoregions from east to west. The northern-most boundaries of five ecoregions dangle from the Interstate: Blue Mountains, Columbia Plateau, Eastern Cascades, Cascades, Willamette Valley, and Coast Range. Our travels provided mere glimpses of five of these gems as we passed through them on the final leg of our six state road trip. I will not write a detailed post for each of those regions now… that is inspiration for future trips to explore my state’s ecoregions in more detail.

This collection of photo galleries is merely one string from the multi-faceted strands of Oregon’s Necklace of Ecoregions…

Snake River Plain: Idaho Border – Farewell Bend (Details for this ecoregion were included in previous post On the Road: Idaho/Oregon Ecoregions- Snake River Plain. )

Blue Mountains: Pleasant Valley – Mecham

The Blue Mountains are a complex of mountain ranges that are mostly volcanic in origin. However, the core of the Blues and the highest ranges, the Wallowa and Elkhorn Mountains, are composed of granite intrusives, deep sea sediments, and metamorphosed rocks. Much of this ecoregion is grazed by cattle.

Columbia Plateau: Mecham – The Dalles

The Columbia Plateau is an arid sagebrush steppe and grassland. It is underlain by basalt that can be up to two miles thick and partially covered by thick loess deposits.  Where precipitation amounts are sufficient, the deep loess soils are cultivated for wheat.

Eastern Cascades Slopes & Foothills: The Dalles – Hood River

This ecoregion is in the rainshadow of the Cascade Range and, as such, the vegetation is adapted to the prevailing dry, continental climate and frequent fire. Open forests of Ponderosa pine and some lodgepole pine distinguish this region from the higher elevations of the Cascades to the west.

Such is the light of day… I shot photos until the setting sun put an end to picture-taking. The remaining ecoregions are inspiration for day trips; as we are very close to home…

Cascades: Hood River – Troutdale

The western Cascades are widely underlain by Cenozoic volcanic rocks and have been affected by alpine glaciation. Maximum elevations of up to 11, 239 feet occur on active and dormant volcanic peaks in the eastern part of this ecoregion. A moist, temperate climate supports an extensive and highly productive coniferous forest that is intensively managed for logging. Subalpine meadows are found in high elevations.

Willamette Valley: Troutdale – Deer Island (We turned off on Sunset Highway 26 to Hillsboro)

Originally, the Willamette Valley was covered by prairies, oak savanna, coniferous forests, extensive wetlands, and deciduous riparian forests. Today, the Willamette Valley contains the build of Oregon’s population, industry, commerce, and cropland. Productive soils and a temperate climate make it one of the most import and agricultural areas in Oregon.


Just Another Nature Enthusiast Photography by Jane Wilson is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

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