Columbia Plateau is a region covering more than 200,000 square miles (518,000 sq km) in Washington, Oregon, and Idaho. It is bordered on the west by the Cascade Range, on the south by the Basin and Range region, and on the east and north by the Rocky Mountains. The plateau derives its name from the fact that it is drained by the Columbia River and its tributaries, which in many cases flow in deep gorges and canyons. The Snake River, on the eastern margin, flows through a canyon one mile (1.6 km) deep.
The surface of the region is not a
simple plateau. It includes plains and basins at low elevations; small plateaus, some level and some sloping; hill lands, both gently rolling and rough; and rugged mountain ranges rising above 10,000 feet (3,000 meters). The names of some of the subdivisions suggest the variety of landforms: the Yakima Folds, central Washington; the Channeled Scablands, eastern Washington; the Deschutes-Umatilla Plateau, north central Oregon; the Wallowa Mountains, northeastern Oregon; the High Lava Plains, central Oregon; and the Snake River Plain, southern Idaho.The climate is generally warm in summer and cold in winter. Precipitation ranges from less than 10 inches (254 mm) in the south to more than 50 inches (1,270 mm) on the slopes of the higher mountains. The lower plains are cultivated intensively with irrigation from the rivers, producing fruits, sugar beets, potatoes, grains, forage crops, and many others. The semiarid areas produce winter and spring wheat and other small grains. In many of the rougher and drier areas grazing is the principal land use. The slopes of the mountains furnish lumber, principally from ponderosa and other pines. The chief cities of the plateau are Spokane and Yakima, Wash.; Pendleton, Ore.; and Boise, Pocatello, and Idaho Falls, Idaho. That’s it, I hope you find this useful. Thanks for reading.
Reff: Samuel Dicken “American Plateau” 2008. University of Oregon