Malheur-Owyhee Upland

region, Oregon, United States

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June 30, 2026

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The Malheur-Owyhee Upland is a region in southeastern Oregon, United States. It is characterized as a high, warped plateau that has experienced more erosion than the nearby High Lava Plains. This area contains older lava flows and is primarily drained by the Owyhee River. The Owyhee River has carved notable canyons in a section known as the Rimrock Country. In the eastern part of the Malheur-Owyhee Upland, along the Snake River, highly productive irrigation agriculture supplements the area's livestock grazing. The region's vegetation includes ponderosa pine, sagebrush, and juniper, with grasses and wildflowers in some areas.123

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Oregon
Relief and drainage
The Malheur-Owyhee Upland of southeastern Oregon is generally a high, warped plateau. It contains older lava and has been more eroded than the High Lava Plains. The major drainage system, the Owyhee River, has incised several notable canyons in an area locally called the Rimrock Country.…
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The Malheur-Owyhee Upland of southeastern Oregon is generally a high, warped plateau. It contains older lava and has been more eroded than the High Lava Plains. The major drainage system, the Owyhee River, has incised several notable canyons in an area locally called the Rimrock Country.…
Read More