Cities and towns in northern California with more than 50,000 inhabitants by population - Metropolitan areas (2010)

Northern California is home to three of the state's four extended metropolitan areas that are home to over three-fourths of the region's population as of the 2010 United States Census:

Reference 1: Population.

Reference 2: San Francisco Bay Area, Greater Sacramento and Metropolitan Fresno.

Source: http://en.wikipedia.org/wiki/Northern_California