San Mateo County – Atherton – 94027 – CA 

Atherton is an incorporated town in San Mateo County, California, United States. Its population was 6,914 at the 2010 census. In October 2013, Forbes magazine placed Atherton’s zip code of 94027 at #1 on its annual list of America’s most expensive zip codes.^[8] Atherton is one of the wealthiest cities in the United States.

Cities: Atherton, CA (96.54%), Woodside, CA (3.14%), North Fair Oaks, CA (0.10%)
County: San Mateo County, CA

Estimated zip code population in 2011: 7,028
Zip code population in 2010: 7,089
Zip code population in 2000: 6,857