What is the region of san francisco?

The San Francisco Bay Area, often referred to as the Bay Area, is a populous region surrounding the US city of San Francisco that encompasses most of the northern part of the U.S. state of California.

It is defined as the nine-county San Francisco Bay Area Combined Statistical Area (CSA) by the United States Census Bureau.

Home to many prominent American companies and institutions, it has some of the highest housing costs and income inequality of any region in the United States.

Counties

The nine counties covered by the San Francisco Bay Area Census CSA are:

- Alameda County

- Contra Costa County

- Marin County

- Napa County

- San Francisco County

- San Mateo County

- Santa Clara County

- Solano County

- Sonoma County

Other Bay Area Definitions

The Bay Area is also sometimes defined more restrictively as the following eight counties comprising the San Francisco–Oakland–San Jose Combined Statistical Area (CBSA):

- Alameda County

- Contra Costa County

- Marin County

- Napa County

- San Francisco County

- San Mateo County

- Santa Clara County

- Solano County

This excludes Sonoma County to the north and the rural eastern suburbs of the Bay Area in Contra Costa County (San Ramon, Orinda, Lafayette, and Moraga) as well as the East County towns in Alameda County (Livermore, Pleasanton, and Dublin) and the East County in Contra Costa County (Brentwood, and Discovery Bay).

Yet another, very restrictive definition of the Bay Area, uses the nine-county San Francisco–San Jose–Oakland Metropolitan Statistical Area (MSA), which excludes the counties on the North Bay (Napa and Sonoma) and the northern and eastern suburbs of the Bay Area (the North of Contra Costa County, and East County of Alameda County). Therefore the nine-county MSA only includes:

- Alameda County

- Contra Costa County (the western and central regions, excluding the North Bay and the East Bay)

- Marin County

- San Francisco County

- San Mateo County

- Santa Clara County