It must not be thought that each site represented on the map by a dot was inhabited in 1769, or the years immediately preceding, for many of the mounds are known to have been formed during the Middle Culture period, which antedated modern times by several centuries. The chief physical characteristic of these accumulations is the very high content of mussel, and to some extent clam, shell. From this feature it has been deduced that at one time a very large population existed along the shore of the Bay.
The record of known sites, as shown on map 1, is valuable, not as an indication of the size of population, but rather of its distribution. Admitting that perhaps the majority of the sites along the Bay shore from San Leandro to Crockett were abandoned before 1770, it is still apparent that the areas designated on the map as Alamedan and Huchiun contained a heavy concentration of inhabited spots. This conclusion is in conformity with the waterfront habitat and the probable large food reserves. Along the strait and the southern shore of Suisun Bay the known habitation mounds are less numerous, but there are enough to indicate a reasonably high population density. This area on the map has been ascribed to Karquin.
Through the generally hilly interior of Alameda and Contra Costa counties there are but two areas of sizable extent in which preconquest village sites occur with relative frequency. One is the Lafayette-Walnut Creek-Danville region and the other the Livermore Valley, west to Pleasanton and Dublin. These provinces were inhabited in the late eighteenth century by the Saklan and Seunen respectively, and are so designated on the map. Indeed, the correspondence between archaeological sites and the occurrence of rancherias in early colonial times is remarkably close. The conclusion is permissible that the pattern of occupancy found by the Spaniards had been established long previously and was fully stabilized at the time of their arrival. This condition in turn argues a mature balance between the natural environment and the indigenous population.
BIBLIOGRAPHY
Abbreviations
| BAE-B | Bureau of Ethnology, Bulletin |
| UC | University of California Publications |
| -AR | Anthropological Records |
| -PAAE | American Archaeology and Ethnology |