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© Pete Saloutos/Panoramic Images (Washington Title Image Large)

Columbia Plateau: People in the Ecoregion

Human history in the Columbia Plateau dates back at least 13,000 years and possibly even earlier. For at least 5,000 years, the native peoples of the region lived in villages along the rivers. They relied on salmon fishing, root and berry harvesting, and hunting. They burned large areas to promote good berry and game habitat, and after the introduction of the horse in the mid-1700s, to improve grazing.

Two hundred years ago, Lewis and Clark encountered numerous Columbia Plateau peoples, including the Cayuse, Nez Perce, Palouse, Tenino, Umatilla, Walla Walla, Wanapum, and Yakama. The Yakama Nation remains a large landholder in the ecoregion.

By the mid-nineteenth century, Euro-American settlers began arriving, with in-migration peaking between 1875 and 1925. They put the region’s abundant natural resources to use with timber harvesting, dryland and irrigated agriculture, grazing, and dam construction.

The mid-twentieth century brought tremendous changes. The Columbia Basin Project built Grand Coulee Dam, among others, with the resulting changes to the basin’s hydrology. The Hanford Nuclear Reservation, once a key participant in the nation’s atomic weapons program, introduced radioactive waste to the issues facing the area.

Today the ecoregion is home to 900,000 people. Agriculture, a vital component of Washington’s economy, has had considerable impact on the biodiversity of the Columbia Plateau. More than half the region’s land base has been converted to dryland or irrigated agriculture and urban development.

Despite the numerous changes in the landscape, sizable pieces of the Columbia Plateau’s natural heritage remain. The U.S. Department of Defense’s Yakima Training Center and the Department of Energy’s Hanford Site retain some of the most intact examples of the region’s shrub-steppe.


For details of this ecoregion within Washington, click a subheading in the left column.

View the more general description of this ecoregion in North America

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