1. California, (Nevada Co.), Nevada City special map Maps Stanford University Public content Geological Survey (U.S.) and Thompson, A. H. (Almon Harris), 1839-1906. Relief shown by contours. Contour interval 20 feet. "A.H. Thompson, Geographer ; E.M. Douglas, Topographer in charge ; Triangulation by E.M. Dougla... U.S. Geological Survey.