Starting with the idea that Tarascan civilization reached its apogee during the seventy years preceding the Spanish conquest, the authors attempt to explain the reasons for this success by investigating the development, structure, and functioning of Tarascan institutions. As a basis for this analysis, they first attempt to assess the natural resources of the Lake Pátzcuaro Basin—the Tarascan core—by classifying the area into ecological zones. They then present data on the size of the population and its spatial distribution in each zone, ranking the settlements by size, social stratification, and type of religious activity. Network analysis is applied to this data base, focusing on economic, administrative, and transportation networks.

The main conclusion is that the administrative network was given priority by the Tarascan leadership, and, with the development of efficient, highly centralized control over the Lake Pátzcuaro Basin with its rich resources and high population density, a power base was created that made it possible subsequently to extend control over a large geographic territory and resist conquest by the neighboring Aztec state. According to the analysis, a large part of this administrative strength lay in the nature of the settlement system in which more than 85 percent of Lake Pátzcuaro Basin’s population lived in large centers, particularly the primate center, facilitating control within the basin and, through these centers, of the population and resources in the outlying territory.

The authors use a combination of archaeological, ethnohistorical, ethnographical, and ecological data from manuscripts and published sources and from field observations carried out during 1976 and 1977. The single most important source of information is the Relación de Michoacan, an ethnohistorical document generally thought to have been produced about 1540. The scarcity of data on the protohistoric period led the authors to use their reconstruction of the early Hispanic period along with modern field and remote sensing data to fill in the gaps.

Although conclusions seem tenuous in view of the scarcity of data from the period under study and the need to extrapolate so much from historic and modem data, the use of geographic techniques of analysis provides an interesting and different approach to understanding a protohistoric society.

Generous use is made of maps, and detailed data on the environment, resources, settlements, and productivity of the Lake Pátzcuaro Basin are included in five appendixes, which make up about one-third of this monograph.