- Geological Survey (U.S.)15
- National Atlas of the United States13
- EROS Data Center9
- Rumsey, David, 1944-3
- Stanford Geospatial Center3
- California. Division of Mines and Geology2
- Garcia, Paul2
- Price, Matt2
- Sacramento County GIS2
- Armstrong, Jake H.1
- Boschke, A.1
- California Geological Survey1
- California. Department of Conservation1
- County of San Mateo Information Services Department1
- Eddy, William Marston1
- Rosenberg, Lewis I.1
- Southern Pacific Company1
- USGS National Center for EROS1
- Viele, Egbert L. (Egbert Ludovicus), 1825-19021
