Contra Costa County is a county located in the state of California. Based on the 2010 census, the
population was 1,049,025. The county
seat is Martinez. The County of Contra Costa,
California (the "County") was created in 1850. The
name is Spanish for "opposite coast", its located
across San Francisco Bay from San Francisco.
Contra Costa County is included in the San Francisco-Oakland-Hayward, CA Metropolitan Statistical Area. It occupies the northern portion of the East Bay region and is primarily suburban.
The name signifies "opposite coast," because it is situated opposite San Francisco, east, on San Francisco Bay. In 1853, Alameda County was formed from territory originally included in this county.
County QuickFacts: Census Bureau Quick Facts
The County of Contra Costa, California (the "County") was incorporated in 1850 as one of the original 27 counties of the State of California (the "State"), with the City of Martinez as the County Seat. Contra Costa is one of the nine counties in the San Francisco-Oakland Bay Area. The County is the ninth most populous county in California, with its population attaining approximately 1,051,677 as of January 1, 2008.
As reported by the Census Bureau, the county has a total area of 802 square miles (2,078 km2), of which, 720 square miles (1,865 km2) of it is land and 82 square miles (213 km2) of it (10.25%) is water.
It is one of the nine counties in the San Francisco-Oakland Bay
Bordering counties are as follows: