This cultural and historical geography of Sonora explores the region’s dual personality—with modern life existing alongside its colonial past. A land where some streams ran with gold. A landscape nearly empty of inhabitants in the wake of Apache raids from the north. And a former desert transformed by irrigation into vast fields of wheat and cotton. This was and is the state of Sonora in northwest Mexico. Robert C. West explores the dual geographic "personality" of this part of Mexico's northern frontier. Utilizing the idea of "old" and "new" landscapes, he describes two Sonoras—to the east, a semiarid to subhumid mountainous region that reached its peak of development in the colonial era; and, to the west, a desert region that has become a major agricultural producer and the modern center of economic and cultural activity. After a description of the physical and biotic aspects of Sonora, West describes the aboriginal farming cultures that inhabited eastern Sonora before the Spanish conquest. He then traces the spread of Jesuit missions and Spanish mining and ranching communities. He charts the decline of eastern Sonora with the coming of Apache and Seri raids during the eighteenth and nineteenth centuries. And he shows how western Sonora became one of Mexico's most powerful political and economic entities in the twentieth century.