Although much has been published on the Nez Perce Indians, there have been relatively few scholarly works focusing on the Indians of the Northwest Plateau. The two major language families on the Columbia Plateau are Sahaptin and Salish. This bibliography concentrates primarily on the former, providing detailed annotations of sources dealing with the Yakima, Palouse, Cayuse, Umatilla, Walla Walla, and Wanapum Indians. It is largely a historical bibliography, although some sources include information pertinent to geographers, anthropologists, economists, and biologists. The work includes secondary sources and a selected number of primary U.S. government documents.