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.