The Indians of California, in their ethnographic present, offered the widest cultural range to be found in any area of the United States. In the north they approximated the cultures of the Northwest Coast; in the center they developed distinctive, elaborate cultures based on local food supplies; and in the south and east they approximated the more primitive desert groups all in all showing a host of adaptations within a relatively small geographical area. In addition, despite successive decimations by missionaries, colonial administrations, settlers, and exploiters, enough Indians survived (though sometimes only a couple of each group) to make their study possible. For these reasons they have long been an important topic in anthropological circles.
Far and away the most important work ever prepared about this complex situation was the monumental "Handbook of the Indians of California" by Kroeber. Based on more than 15 years of exhaustive research by Kroeber, it is a summation of just about everything of importance known about these Indians. Kroeber covered demographic situations, linguistic relations (which are also extraordinarily complex), social structures, folkways, religion, material culture, and whatever else was needed to offer a full picture of each tribe. The resulting book is a survey of each group, the typologically more important groups like the Yurok, Pomo, Maidu, Yokuts, and Mohave naturally receiving the most detail. Indispensable for every student of the American Indian, it can be read with great profit by both specialists and lay readers."