The plateau area stretches from central British Columbia, south and across the United States border, eastern Washington and Oregon, then across the Continental Divide into northwestern Montana. The Columbia River which runs through the Bitterroot and Blue Mountains is the lifeblood of the land and its people. These rivers are rich in fish resources which Plateau peoples subsidize on; along with roots, berries, and game. They followed a season round of gathering. The Plateau Region was dominated by two major linguistic groups: in the north were the Salishan-speaking Shuswap, Lillooet, Thompson and Okanagan, while across the border into present-day Washington and Idaho lived the Kalispel, Coeur d'Alene, Spokane, Colville, Sanpoil and flathead. In the central Columbia ranged the Klickitat, Yakima, Umatilla, Walla Walla, Palus, Nez Perce, and Cayuse.