Humans may have been present in Idaho for 16,600 years. Recent findings in Cooper's Ferry along the Salmon River in western Idaho near the town of Cottonwood have unearthed stone tools and animal bone fragments in what may be the oldest evidence of humans in North America.[1][2][3][4][5] Earlier excavations in 1959 at Wilson Butte Cave near Twin Falls revealed evidence of human activity, including arrowheads, that rank among the oldest dated artifacts in North America.[6] American Indian tribes predominant in the area in historic times included the Nez Perce and the Coeur d'Alene in the north; and the Northern and Western Shoshone and Bannock peoples in the south.