In the last century historians and anthropologists interested in northwestern Mexico knew that Indians had inhabited four large islands in the Gulf of California. Since 1900 ethnohistorical and archaeological research has expanded knowledge of Indians on both sides of the Gulf. Much of that information pertains to the people living on the peninsula and mainland, and touches only incidentally on the islands. In this volume, Thomas Bowen presents historical and archaeological evidence for human use of 32 major Gulf islands. Native people may have played a significant role in shaping island ecosystems. Chronological data from the southern Gulf establishes a time depth for native people of ten millennia. New information from Seri oral history indicates Seri voyages far beyond Isla Tiburon, and Bowen shows the traditional assumption -- that most islands were beyond the range of native people - is wrong. Indians knew and exploited nearly every significant island in the Gulf. Bowen's work touches on the question of initial human entry into the Americas. The Gulf may occupy a pivotal position in human dispersal in the Americas, and it is possible that evidence of this process has been preserved on some Gulf islands.