https://www.mercurynews.com/2020/03/04/map-coronavirus-cases-in-the-bay-area-northern-california/

California counties are seeing a rise in coronavirus cases as COVID-19 continues its spread within communities. The map below shows the cumulative number of coronavirus cases recorded in Bay Area and other Northern California counties where cases have been found. Any deaths will be noted in the county summary.

These numbers are based on information provided by county public health departments. Note: There may be some duplication in the county numbers. For example, when a patient is moved from one county to another for treatment, the case may be recorded in both counties.