2012. von Dohlen, Jerry. This polygon shapefile depicts the administrative boundaries and Spheres of Influence for Cities over which the County of Humboldt, California hold... Humboldt County Planning and Building Department.
2015. Monterey County (Calif.). This polygon shapefile contains spheres of influence in Monterey County, California. City and special district spheres of influence define the prob... Monterey County (Calif.).
2015. Garcia, Paul and Price, Matt. This polygon shapefile depicts spheres of influence (SOI) associated with incorporated areas in the County of Santa Cruz, California: Capitola, San... County of Santa Cruz Information Services Department.
2015. Armstrong, Jake H. This polygon shapefile depicts Spheres of Influence (SOI) boundaries associated with incorporated areas in the County of Solano, California. These ... Solano County Department of Information Technology.