The Plateau is a designation used for both a physiographic region and a regional pattern of prehistoric cultural adaptations. The Columbia Plateau physiographic region lies between the Rocky Mountains and the Cascade Mountains. The Plateau cultures developed within the Columbia Plateau which includes the areas drained by the Fraser, Columbia, and Snake rivers. The northern border of the culture area lies in Canada where the Plateau gives way to Arctic culture patterns. The southern portion of the Plateau mixes gradually with the Great Basin culture adaptations.
At the Pacific Crest, the Plateau pattern is contrasted by the Northwest Coast cultures while the Plains adaptations prevail east of the Continental Divide. The late prehistoric evidence and ethnographic accounts of the Plateau cultures show a focus on riverine resources and trade routes. Seasonal movement of the people concentrated on obtaining resources during peak times of production and storage for use during less productive periods. Although people of the Plateau interacted and traded with neighbors on all sides, physiography affected the resources available and influenced the indigenous cultures.