Original vintage geological map of the San Pablo Bay, in the upper Bay Area. Showing an area of some 100 square miles in size in great detail, this map includes an extremely detailed early look at the geology of the region. The map shows topography, settlements, and more. The map was produced by the USGS based on information compiled by Charles E. Weaver.
The map centers on Mare Island, and Vallejo is shown with its grid structure. Napa Junction and Shellville also appear.
The geology of this region includes many intrusive and extrusive igneous rocks in the west, typical of the coast ranges of central and northern California. In the rest of the map, very young sedimentary rocks are visible.