Plateau/Great Basin Peoples

The top map shows the names of the tribes considered to be Plateau peoples with the exception of the Modoc and Klamath who are considered Great Basin peoples. The bottom map shows the homelands of the tribes that are considered to be residents of the Great Basin, but it lacks the Klamath and the Modoc.  The uniting element is that they all lived in the semi-arid lands that form the "rain-shadow" to the East of the tall and steep ranges of mountains, the Cascades and the Sierra Nevada.  Impassable in winter, these mountains created a natural boundary that determined who traded, talked, or fought with whom when and blocked easy access to the warmer coastal facing slopes and valleys.