Bay Area: Includes the counties in the San Francisco Bay Area, which are more metropolitan counties with a strong industrial component in the economy.
Coastal: Includes the counties on or near the coast that were not in either the Bay Area or Southern Regions. The Coastal Region is more populated than the rural Mountain Region and has a large agricultural component similar to the Central Valley.
Mountain: Includes counties that are primarily rural, with strong agricultural economies, low population density, and a low industrial base.
Southern: Includes counties that are strongly industrial with large populations and some agricultural influences.
Valley: Includes counties between the Sierra Nevada Mountains and the Coast Range that have a major agricultural base with important population centers and some manufacturing.
