Dictionary.net

a large plateau south and west of the Rocky Mountains; abuts mountains on the north and east and ends in an escarpment overlooking lowlands to the south and west; the Grand Canyon of the Colorado River is carved out of the southwestern corner

a large plateau south and west of the Rocky Mountains; abuts mountains on the north and east and ends in an escarpment overlooking lowlands to the south and west; the Grand Canyon is carved out of the southwestern corner