As a result of work on Santa Rosa Island during 1947-1950, the Santa Barbara Museum of Natural History has completed a survey which includes 142 ancient Indian village sites. On the California mainland intensive cultivation, construction and pot-hunting have pretty well eliminated the natural surface conditions of Indian sites, but on Santa Rosa Island, due to its isolation, there are many sites untouched by modern man. Consequently, it was possible to set up a system of classification of the sites undisturbed by civilization on a basis of natural physical conditions.