The County of Alameda has a population of 1,510,271 and is a member of the East Bay Planning Hub. The Hayward Fault, a major branch of the San Andreas Fault, runs through the most populated parts of the county, and the Calaveras Fault runs through the southeastern part of the county. The County of Alameda is also home to the University of California, Berkeley and twelve other prominent colleges and universities.

The County of Contra Costa is located east of the San Pablo and San Francisco Bay, has a population of 1,049,025, and is a member of the East Bay Planning Hub. Four slip-strike earthquake faults (the Hayward Fault Zone, Calaveras Fault, Concord Fault, and Clayton-Marsh Creek-Greenville Fault) as well as the Diablo thrust fault run through this county and cross critical infrastructure and key resources, such as petroleum product pipelines, roads, highways, railroads, and BART rail transit.

The County of Marin, located north of the Golden Gate Bridge, has a population of 252,400 and is a member of the North Bay Planning Hub. Critical infrastructure and key resources include: San Quentin Prison, Skywalker Ranch, Autodesk, and the Marin County Civic Center designed by Frank Lloyd Wright. The county is home to natural sites such as Muir Woods, the Marin Headlands, Stinson Beach, the Point Reyes National Seashore, and Mount Tamalpais.

The County of Monterey is located on the Pacific coast, has a population of 415,057, and is a member of the South Bay Planning Hub.  The county is served by Amtrak trains and Greyhound Lines buses as well as U.S. Route 101 and six State Routes. 

The County of Napa is located north of the San Pablo Bay, has a population of 136,484, and is a member of the North Bay Planning Hub. The county is known for its first-rank wine industry and its rural agricultural environment. Five State Routes, two local airports, and the Napa Valley Railroad run through the county.

The City of Oakland is located in the County of Alameda, has a population of 395,817, is a member of the Easy Bay Planning Hub, and is a core city. Oakland is a major west coast port city and the busiest port for the Bay Area and Northern California. It is a major hub for transportation and trade as well as culture and professional sports.

The County of San Benito is located in the Cost Range Mountains, has a population of 55,269, and is a member of the South Bay Planning Hub. Mount Harlan, San Benito American Viticultural Areas, and the Pinnacles National Monument are located in this county. U.S. Route 101 Federal highway and four State Routes run through the County of San Benito

The County of Santa Clara is located at the southern end of the San Francisco Bay Area, has a population of 1,781,642, and is a member of the South Bay Planning Hub. The highly urbanized Silicon Valley is located in this county and is the headquarters for companies such as Apple, Facebook, Sun Microsystems, Hewlett Packard, Google, and Cisco Systems. The San Andreas Fault runs along the southern area of the county.

The County of Santa Cruz is located on the California Central Coast, has a population of 262,382, and is a member of the South Bay Planning Hub.  It is home to the University of California, Santa Cruz and winemaking is an important part of the economic and cultural life of this county. The San Andreas Fault runs along the Santa Cruz Mountains. 

The City and County of San Francisco has a population of 805,235, a density of 17,179.2/sq mi, is a member of the West Bay Planning Hub, and is a core city. San Francisco has critical resources such as the Golden Bridge, the Transamerica Building, and other leading financial and cultural centers. It is the home of several professional sports teams such as the 49ers and the Giants. Numerous public transit agencies and hubs run through San Francisco, including MUNI, BART, and the Port of San Francisco.

The City of San Jose is located in the County of Santa Clara, has a population of 971,372, is a member of the South Bay Planning Hub, and is a core city. It maintains a global city status as the “Capital of Silicon Valley” and is the largest city in the San Francisco Bay Area based on its population, land area, and industrial development. Critical infrastructure and key resources include: the HP Pavilion, Lick Observatory, San Jose City Hall, and the San Jose International Airport.

The County of San Mateo is located along the San Francisco Peninsula, has a population of 718,451, and is a member of the West Bay Planning Hub. The San Francisco International Airport is located in the northern end of the county and Silicon Valley begins at the southern end. While the county is predominantly suburban, some areas are very urban and home to corporate campuses. Caltrain, Highway 101, and BART traverse through this county.

The County of Solano is the easternmost county in the North Bay of the San Francisco Bay Area, has a population of 413,344, and is a member of the North Bay Planning Hub. The southern campus of the University of California, Davis is located in this county and four Interstate highways and five State Routes run through it. There are also BART station connections and several rapid bus and ferry public transit agencies.

The County of Sonoma is the northernmost county in the San Francisco Bay Area, has a population of 484,470, and is a member of the North Bay Planning Hub. It is home to the Charles M. Schultz Sonoma County Airport. U.S. Route 101 Federal highway and six State Routes run through it. It is the largest producer of California’s Wine County region and is ranked as the eighth most agriculturally productive U.S. county.