Sonoma is the southwestern county of California's Wine Country region, which also includes Napa, Mendocino, and Lake counties. It has thirteen approved American Viticultural Areas and over 250 wineries. In 2002 Sonoma County ranked as the thirty-second county in the United States in agricultural production. As early as 1920 Sonoma County was ranked as the eighth most agriculturally productive U.S county and a leading producer of poultry products, hops, grapes, prunes, apples, and dairy products, largely due to the abundance of high quality irrigation water. More than 7.4 million tourists visit each year, spending more than $1 billion in 2006. Sonoma County is the home of Sonoma State University and Santa Rosa Junior College.
Sonoma County was once home to several Native American tribes, who lived within the carrying capacity of the land; by 1850, European settlement had set a new direction that would prove to radically alter the course of land use and resource management of this region. As of 2007, Sonoma County has rich agricultural land, albeit now largely divided between two nearly monocultural uses: grapes and pasturage. The voters have twice approved open space initiatives that have provided funding for public acquisition of natural areas, preserving forested areas, coastal habitat, and other open space.
At the 2000 census, there were 458,614 people, 172,403 households, and 112,406 families in Sonoma County. The population density was 291/sq mi (112/km²). There were 183,153 housing units at an average density of 116/sq mi (45/km²).
The racial makeup was 81.60% White, 1.42% Black or African American, 1.18% Native American, 3.07% Asian, 0.20% Pacific Islander, 8.44% of other races, and 4.09% of two or more races. 17.34% of the population were Hispanic or Latino of any race. 12.1% were of German, 10.6% Irish, 9.8% English and 8.9% Italian ancestry according to Census 2000. 80.4% spoke English and 13.8% Spanish as their first language.
Of the 172,403 households, 50.30% were married couples living together, 34.80% were non-families, and 10.40% had a female householder with no husband present. 31.90% had children under the age of 18 living with them, 25.70% were individuals, and 10.00% were 65 years of age or older living alone. The average household size was 2.60, and the average family size was 3.12.
The median age was 38 years. 24.50% were under 18, 8.80% from 18 to 24, 29.20% from 25 to 44, 24.90% from 45 to 64, and 12.60% were 65 years of age or older. For every 100 females there were 97 males. For every 100 females age 18 and over, there were 94 males.
The median household income was $53,076, and the median family income was $61,921. Males had a median income of $42,035, females $32,022. The per capita income for the county was $25,724. About 4.70% of families and 8.10% of the population were below the poverty line, including 8.40% of those under age 18 and 5.70% of those age 65 or over.
U.S. Route 101
U.S. Route 101 is the westernmost Federal highway in the U.S.A. Running north/south through the states of California, Oregon, and Washington, it generally parallels the coastline from the Mexican border to the Canadian border. Highway 101 links seven of the county's nine incorporated cities: Cloverdale, Healdsburg, Windsor, Santa Rosa, Rohnert Park, Cotati, and Petaluma. It is a freeway for almost its entire length within the county, except for a section south of Petaluma.
The four-lane sections of the highway have been heavily congested during peak commute hours for many years. The part of the highway between Santa Rosa and Rohnert Park was widened to six lanes, with the section within Santa Rosa (between Highway 12 and Steele Lane) being completed in late 2008. The two new inner lanes are designated for vehicles with two or more occupants during commute hours. The next section due to be expanded from four to six lanes is between Santa Rosa and Windsor.
State Route 1
Within Sonoma County, Highway 1 follows the coastline from the Mendocino County border, at the mouth of the Gualala River, to the Marin County border, at the Estero Americano (Americano Creek), east of Bodega Bay.
State Route 12
Highway 12 runs eastward from its intersection with Highway 116 in Sebastopol to Santa Rosa. There it turns south through the Valley of the Moon to Sonoma, then east into Napa County. The four-lane freeway section within Santa Rosa, between Fulton Road and Farmers Lane, is called the Luther Burbank Memorial Highway. That section, especially where it crosses Highway 101, is severely congested during peak commute hours.
The two-lane Bodega Highway runs west from the intersection of Highways 12 and 116 in Sebastopol, through the coastal hills to its intersection with Highway 1, east of Bodega Bay. East of Santa Rosa, Highway 12 is also called Sonoma Highway; and east of Sonoma, Carneros Highway.
State Route 37
Highway 37 connects Highway 101 at Novato, in Marin County, with Interstate 80 in Vallejo, in Solano County, at the top of San Pablo Bay. Within Sonoma County, it is also called Sears Point Road.
State Route 116
Highway 116 is a winding, two-lane rural route that runs from Jenner, at the mouth of the Russian River on the coast, southeast to Arnold Drive near Sonoma. It is also called Guerneville Highway, between Guerneville and Forestville; Gravenstein Highway North, between Forestville and Sebastopol; and Gravenstein Highway South, between Sebastopol and Stony Point Road, west of Rohnert Park. East of Petaluma it is Lakeville Highway, then Stage Gulch Road.
State Route 121
Highway 121 is a two-lane rural route running from Highway 37 near Sears Point Raceway to Highway 128 in Lake Berryessa.
State Route 128
The northernmost section of Highway 128 is a two-lane rural route running southeast from Highway 101 at Geyserville, north of Healdsburg, through the Alexander Valley into Napa County.
Sonoma-Marin Area Rail Transit/SMART is a commuter rail system planned to go between Larkspur in Marin County and Cloverdale in Sonoma County. A sales tax surcharge measure to finance it narrowly failed in the 2006 election, but passed in 2008.