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 (https://castrovalleycity.com/, 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.