Bethel Island, CA
Bethel Island (formerly, Bethell) is a census-designated place (CDP) on Bethel Island in Contra Costa County, California, United States. The population was 2,137 at the 2010 census.
According to the United States Census Bureau, the CDP has a total area of 5.1 square miles (13.3 km²), all of it land. It is located on an island of the same name 9 miles (14 km) east of Antioch.
The first post office opened in 1897, and named for its first postmaster Franklin C. Bethell. The post office closed in 1902. The Bethel Island post office opened in 1947.