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Castro Valley

Castro Valley is the largest unincorporated community in Alameda County. With 67,000 residents, it is the fifth most populous unincorporated area in California and the twenty-third most populous unincorporated area in the United States. As intensely developed as the community is, many people think Castro Valley is a city. But it is just another Census Designated Place controlled by the Alameda County Board of Supervisors. The residents and businesses of Castro Valley do not have a Mayor and a City Council to attend to local issues. For more information, see the Castro Valley City website (, an active site that has been responding to the 2023 Alameda County LAFCO feasibility study), the Castro Valley City Facebook page and the Castro Valley Matters blog.

May contain: road, freeway, intersection, city, tarmac, car, transportation, vehicle, highway, urban, machine, and wheel


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