The Palouse (pəˈluːs ) is a distinct geographic region of the northwestern United States, encompassing parts of north central Idaho, southeastern Washington, and, by some definitions, parts of northeast Oregon. It is a major agricultural area, primarily producing wheat and legumes. Situated about north of the Oregon Trail, the region experienced rapid growth in the late 19th century.
The Palouse is home to two land-grant universities: the University of Idaho in Moscow and Washington State University in Pullman. Just eight miles (13 km) apart, both schools opened in the early 1890s.
The origin of the name "Palouse" is unclear. One theory is that the name of the Palus tribe (spelled in early accounts variously as Palus, Palloatpallah, Pelusha, etc.) was converted by French-Canadian fur traders to the more familiar French word pelouse, meaning "land with short and thick grass" or "lawn." Over time, the spelling changed to Palouse. Another theory is that the region's name came from the French word and was later applied to its indigenous inhabitants.
Traditionally, the Palouse region was defined as the fertile hills and prairies north of the Snake River, which separated it from Walla Walla County, and north of the Clearwater River, which separated it from the Camas Prairie, extending north along the Washington and Idaho border, south of Spokane, centered on the Palouse River. This region underwent a settlement and wheat-growing boom during the 1880s, part of a larger process of growing wheat in southeast Washington, originally pioneered in Walla Walla County south of the Snake River.
While this definition of the Palouse remains common today, the term is sometimes used to refer to the entire wheat-growing region, including Walla Walla County, the Camas Prairie of Idaho, the Big Bend region of the central Columbia River Plateau, and other smaller agricultural districts such as Asotin County, Washington, and Umatilla County, Oregon. This larger definition is used by organizations such as the World Wide Fund for Nature, who define the Palouse Grasslands ecoregion broadly.