The hypothesis of an Intermontane Western tradition is advanced as a conceptual framework within which it is possible to achieve a greater understanding of the cultural histories of the Plateau, Great Basin, and Southwest culture areas, including broad and specific relationships and also the developing differences.
Geographically, the Intermontane Western tradition extended throughout the intermontane region between the Cascade-Sierra Nevada ranges on the west, and the Rocky Mountains on the east, and from southern British Columbia on the north to northern Mexico on the south. Temporally, the Intermontane Western tradition existed throughout the post-glacial period.
Within the major tradition, the Southwest Agricultural, Desert, and Northwest Riverine Areal traditions are seen developing, partly in response to environmental changes.