# Solano County, California

Solano County (/səˈlɑːnoʊ/ ) is a county located in the U.S. state of California. As of the 2020 census, its population was 453,491. The county seat is Fairfield.
Solano County comprises the Vallejo–Fairfield metropolitan statistical area, which is also included in the San Jose–San Francisco–Oakland, combined statistical area. Solano County is the northeastern county in the nine-county San Francisco Bay Area region.
A portion of the South Campus at the University of California, Davis, is in Solano County.

## History

Solano County was one of the original counties of California, created in 1850 at the time of statehood.
At the request of General Mariano Guadalupe Vallejo, the county was named for Chief Solano of the Suisun people, a Native American tribe of the region and Vallejo's close ally. Chief Solano at one time led the tribes between the Petaluma River and the Sacramento River. The chief was also called Sem-Yeto, which signifies "brave or fierce hand". The chief was given the Spanish name Francisco Solano during baptism at the Catholic Mission, and is named after the Spanish Franciscan missionary, Father Francisco Solano. "Solano" is a common surname in the north of Spain, especially in Navarra, Zaragoza, and La Rioja.
Travis Air Force Base is located just east of Fairfield. Between 2017 and 2023, California Forever purchased over 50,000 acres of land in the county for an estimated $900 million to develop a new city.

## Region

Solano County is the easternmost county of the North Bay. As such, it is sometimes reported by news agencies as being in the East Bay. Additionally, a portion of the county extends into the Sacramento Valley, geographically.

## Geography

According to the U.S. Census Bureau, the county has a total area of 906 square miles (2,350 km$^2$), of which 84 square miles (220 km$^2$), comprising 9.3%, are covered by water.
Solano County had several cinnabar mines that were worked in the first half of the twentieth century, including the Hastings Mine and St. John's Mine.

### Adjacent counties

* Contra Costa County, California - south
* Sonoma County, California - west
* Napa County, California - west
* Yolo County, California - north
* Sacramento County, California - east

### National protected area

* San Pablo Bay National Wildlife Refuge (part)

### Flora and fauna

Solano County has a number of rare and endangered species, including the Delta green ground beetle, the wildflower Lasthenia conjugens, commonly known as Contra Costa goldfields, and the annual plant Legenere limosa or false Venus' looking glass.

## Transportation
### Major highways

* Interstate 80
* Interstate 505
* Interstate 680
* Interstate 780
* State Route 12
* State Route 29
* State Route 37
* State Route 84
* State Route 113

### Public transportation

Solano County is served by several transit agencies:
* SolTrans, formed as a merger between these two existing transit agencies:
** Vallejo Transit, which also formerly operated the Baylink Ferry to San Francisco
** Benicia Breeze
* San Francisco Bay Ferry, with a terminal in Vallejo
* Fairfield and Suisun Transit
* Vacaville City Coach
* Rio Vista Delta Breeze
Each agency interconnects with the others, enabling transit trips throughout the county. Service also connects with BART stations in Contra Costa County. Transit links are provided to Napa, Yolo and Sacramento counties as well.
Greyhound and Amtrak provide long-distance intercity service.

### Airports

General aviation airports in Solano County that are open to the public are the Nut Tree Airport and Rio Vista Municipal Airport.

## Demographics
### 2020 census

Solano County, California – Racial and ethnic composition Note: the US Census treats Hispanic/Latino as an ethnic category. This table excludes Latinos from the racial categories and assigns them to a separate category. Hispanics/Latinos may be of any race. :
| Race / Ethnicity (NH = Non-Hispanic) | Pop 2010 | Pop 2020 | % 2010 | % 2020 |
| White alone (NH) | 168,628 | 155,125 | 40.80% | 34.21% |
| Black or African American alone (NH) | 58,743 | 60,051 | 14.21% | 13.24% |
| Native American or Alaska Native alone (NH) | 1,864 | 1,624 | 0.45% | 0.36% |
| Asian alone (NH) | 59,027 | 70,953 | 14.28% | 15.65% |
| Pacific Islander alone (NH) | 3,243 | 3,775 | 0.78% | 0.83% |
| Other Race alone (NH) | 1,463 | 2,988 | 0.35% | 0.66% |
| Mixed Race or Multi-Racial (NH) | 21,020 | 30,820 | 5.09% | 6.80% |
| Hispanic or Latino (any race) | 99,356 | 128,155 | 24.04% | 28.26% |
| Total | 413,344 | 453,491 | 100.00% | 100.00% |

### 2014

A 2014 analysis by The Atlantic found Solano County to be the 5th most racially diverse county in the United States, behind Aleutians West Census Area and Aleutians East Borough in Alaska, Queens County in New York, and Alameda County in California.

### 2011

Population, race, and income :
| Total population | 411,620 | 411,620 |
| White | 214,436 | 52.1% |
| Black or African American | 60,130 | 14.6% |
| American Indian or Alaska Native | 2,427 | 0.6% |
| Asian | 59,143 | 14.4% |
| Native Hawaiian or other Pacific Islander | 3,390 | 0.8% |
| Some other race | 43,064 | 10.5% |
| Two or more races | 29,030 | 7.1% |
| Hispanic or Latino (of any race) | 97,268 | 23.6% |
| Per capita income | $29,367 | $29,367 |
| Median household income | $69,914 | $69,914 |
| Median family income | $79,316 | $79,316 |

#### Places by population, race, and income

Places by population and race :
| Place | Type | Population | White | Other | Asian | Black or African American | Native American | Hispanic or Latino (of any race) |
| Allendale | CDP | 1,968 | 86.1% | 10.7% | 3.2% | 0.0% | 0.0% | 14.7% |
| Benicia | City | 26,981 | 75.6% | 10.4% | 9.3% | 3.1% | 1.7% | 12.2% |
| Dixon | City | 18,141 | 74.9% | 17.0% | 3.8% | 3.0% | 1.3% | 39.4% |
| Elmira | CDP | 251 | 97.2% | 2.8% | 0.0% | 0.0% | 0.0% | 2.8% |
| Fairfield | City | 104,404 | 47.1% | 19.4% | 15.5% | 16.6% | 1.5% | 25.7% |
| Green Valley | CDP | 1,719 | 85.7% | 8.7% | 2.4% | 3.1% | 0.0% | 8.0% |
| Hartley | CDP | 2,229 | 85.3% | 4.4% | 1.7% | 7.3% | 1.3% | 12.7% |
| Rio Vista | City | 7,088 | 76.5% | 10.0% | 4.0% | 7.9% | 1.5% | 14.9% |
| Suisun City | City | 27,900 | 34.4% | 24.9% | 19.9% | 19.7% | 1.1% | 25.6% |
| Vacaville | City | 92,217 | 64.8% | 17.0% | 5.9% | 11.1% | 1.2% | 21.7% |
| Vallejo | City | 116,021 | 36.2% | 17.2% | 23.9% | 21.0% | 1.6% | 23.3% |
Places by population and income :
| Place | Type | Population | Per capita income | Median household income | Median family income |
| Allendale | CDP | 1,968 | $41,928 | $112,837 | $119,063 |
| Benicia | City | 26,981 | $41,854 | $90,338 | $102,571 |
| Dixon | City | 18,141 | $27,624 | $72,626 | $76,038 |
| Elmira | CDP | 251 | $22,069 | $73,438 | $85,650 |
| Fairfield | City | 104,404 | $26,785 | $68,037 | $75,717 |
| Green Valley (Solano County) | CDP | 1,719 | $67,828 | $125,669 | $145,781 |
| Hartley | CDP | 2,229 | $41,041 | $87,841 | $106,786 |
| Rio Vista | City | 7,088 | $34,332 | $58,701 | $68,156 |
| Suisun City | City | 27,900 | $26,148 | $71,411 | $76,286 |
| Vacaville | City | 92,217 | $29,687 | $73,302 | $85,790 |
| Vallejo | City | 116,021 | $27,375 | $62,325 | $72,717 |

### 2010

The 2010 United States census reported that Solano County had a population of 413,344. The racial makeup of Solano County was 210,751 (51.0%) White, 60,750 (14.7%) African American, 3,212 (0.8%) Native American, 60,473 (14.6%) Asian, 3,564 (0.9%) Pacific Islander, 43,236 (10.5%) from other races, and 31,358 (7.6%) from two or more races. Hispanic or Latino of any race were 99,356 persons (24.0%). At 52,641 Filipinos in the county making up 12% of the population, Solano County has the largest percentage Filipino population of any county in the United States.
Population racial makeup reported at 2010 United States census :
| County | Total population | White | African American | Native American | Asian | Pacific Islander | Other races | Two or more races | Hispanic or Latino (of any race) |
| Solano County | 413,344 | 210,751 | 60,750 | 3,212 | 60,473 | 3,564 | 43,236 | 31,358 | 99,356 |
| Incorporated cities and towns | Total population | White | African American | Native American | Asian | Pacific Islander | Other races | Two or more races | Hispanic or Latino (of any race) |
| Benicia | 26,997 | 19,568 | 1,510 | 135 | 2,989 | 102 | 895 | 1,798 | 3,248 |
| Dixon | 18,351 | 13,023 | 562 | 184 | 671 | 58 | 2,838 | 1,015 | 7,426 |
| Fairfield | 105,321 | 48,407 | 16,586 | 869 | 15,700 | 1,149 | 13,301 | 9,309 | 28,789 |
| Rio Vista | 7,360 | 6,003 | 372 | 53 | 359 | 15 | 288 | 270 | 914 |
| Suisun City | 28,111 | 10,805 | 5,713 | 196 | 5,348 | 340 | 2,898 | 2,811 | 6,753 |
| Vacaville | 92,428 | 61,301 | 9,510 | 846 | 5,606 | 532 | 8,136 | 6,497 | 21,121 |
| Vallejo | 115,942 | 38,064 | 25,572 | 757 | 28,895 | 1,239 | 12,759 | 8,656 | 26,165 |
| Census-designated places | Total population | White | African American | Native American | Asian | Pacific Islander | Other races | Two or more races | Hispanic or Latino (of any race) |
| Allendale | 1,506 | 1,239 | 49 | 22 | 42 | 2 | 79 | 73 | 235 |
| Elmira | 188 | 150 | 1 | 10 | 2 | 0 | 17 | 8 | 47 |
| Green Valley | 1,625 | 1,412 | 41 | 6 | 82 | 9 | 20 | 55 | 121 |
| Hartley | 2,510 | 1,956 | 70 | 24 | 70 | 16 | 248 | 126 | 510 |
| Other unincorporated areas | Total population | White | African American | Native American | Asian | Pacific Islander | Other races | Two or more races | Hispanic or Latino (of any race) |
| All others not CDPs (combined) | 13,005 | 8,823 | 764 | 110 | 709 | 102 | 1,757 | 740 | 4,027 |

### 2000

At the 2000 census there were 394,542 people, 130,403 households, and 97,411 families in the county. The population density was 476 inhabitants per square mile (184/km$^2$). There were 134,513 housing units at an average density of 162 per square mile (63/km$^2$). The racial makeup of the county was 56.4% White, 14.9% Black or African American, 0.8% Native American, 12.8% Asian, 0.8% Pacific Islander, 8.0% from other races, and 6.4% from two or more races. 17.64% of the population were Hispanic or Latino of any race. 8.5% were of German, 6.4% Irish and 6.0% English ancestry according to Census 2000. 75.7% spoke English, 12.1% Spanish and 6.6% Tagalog as their first language. Of the 130,403 households 39.9% had children under the age of 18 living with them, 55.7% were married couples living together, 13.8% had a female householder with no husband present, and 25.3% were non-families. 19.6% of households were one person and 6.5% were one person aged 65 or older. The average household size was 2.90 and the average family size was 3.33.
The age distribution was 28.3% under the age of 18, 9.2% from 18 to 24, 31.3% from 25 to 44, 21.7% from 45 to 64, and 9.5% 65 or older. The median age was 34 years. For every 100 females there were 101.5 males. For every 100 females age 18 and over, there were 100.2 males.
The median household income was $54,099 and the median family income was $60,597. Males had a median income of $41,787 versus $31,916 for females. The per capita income for the county was $21,731. About 6.1% of families and 8.3% of the population were below the poverty line, including 10.3% of those under age 18 and 6.3% of those age 65 or over.

## Crime

The following table includes the number of incidents reported and the rate per 1,000 persons for each type of offense (2011).
Population and crime rates :
| Population | 411,620 | 411,620 |
| Violent crime | 2,064 | 5.01 |
| Homicide | 20 | 0.05 |
| Forcible rape | 112 | 0.27 |
| Robbery | 810 | 1.97 |
| Aggravated assault | 1,122 | 2.73 |
| Property crime | 8,460 | 20.55 |
| Burglary | 4,168 | 10.13 |
| Larceny-theft | 7,018 | 17.05 |
| Motor vehicle theft | 2,084 | 5.06 |
| Arson | 116 | 0.28 |

### Cities by population and crime rates

Cities by population and crime rates :
| City | Population | Violent crimes | Violent crime rate per 1,000 persons | Property crimes | Property crime rate per 1,000 persons |
| Benicia | 27,459 | 37 | 1.35 | 390 | 14.20 |
| Dixon | 18,708 | 53 | 2.83 | 315 | 16.84 |
| Fairfield | 107,110 | 454 | 4.24 | 3,317 | 30.97 |
| Rio Vista | 7,485 | 39 | 5.21 | 145 | 19.37 |
| Suisun City | 28,593 | 57 | 1.99 | 558 | 19.52 |
| Vacaville | 93,951 | 246 | 2.62 | 2,031 | 21.62 |
| Vallejo | 117,912 | 878 | 7.45 | 5,844 | 49.56 |

## Government and politics
### Government

The Government of Solano County is defined and authorized under the California Constitution and law as a general law county. The County government provides countywide services such as elections and voter registration, law enforcement, jails, vital records, property records, tax collection, public health, and social services. In addition the County serves as the local government for all unincorporated areas.
The County government is composed of the elected five-member Board of Supervisors, several other elected offices including the Sheriff-Coroner, District Attorney, Assessor/Recorder, Auditor-Controller, and Treasurer/Tax Collector/County Clerk, and numerous county departments and entities under the supervision of the County Administrator. As of March 2023, the members of the Solano County Board of Supervisors were:
* Erin Hannigan, District 1
* Monica Brown, District 2, Vice Chair
* Wanda Williams, District 3
* John Vasquez, District 4, Chair
* Mitch Mashburn, District 5

### Politics
#### Voter registration statistics

Population and registered voters :
| Total population | 411,620 | 411,620 |
| Registered voters | 210,453 | 51.1% |
| Democratic | 102,177 | 48.6% |
| Republican | 52,633 | 25.0% |
| Democratic–Republican spread | +49,544 | +23.6% |
| Independent | 5,940 | 2.8% |
| Green | 878 | 0.4% |
| Libertarian | 1,123 | 0.5% |
| Peace and Freedom | 539 | 0.3% |
| Americans Elect | 12 | 0.0% |
| Other | 905 | 0.4% |
| No party preference | 46,246 | 22.0% |
Cities by population and voter registration :
| City | Population | Registered voters | Democratic | Republican | D–R spread | Other | No party preference |
| Benicia | 26,981 | 68.1% | 47.2% | 25.3% | +21.9% | 8.4% | 22.1% |
| Dixon | 18,141 | 50.7% | 38.8% | 35.4% | +3.4% | 7.3% | 21.4% |
| Fairfield | 104,404 | 48.1% | 48.7% | 24.4% | +24.3% | 6.8% | 22.7% |
| Rio Vista | 7,088 | 72.6% | 42.7% | 33.9% | +8.8% | 9.0% | 18.2% |
| Suisun City | 27,900 | 49.1% | 52.4% | 20.2% | +32.2% | 7.0% | 23.2% |
| Vacaville | 92,217 | 50.1% | 39.6% | 33.2% | +6.4% | 8.5% | 22.1% |
| Vallejo | 116,021 | 48.8% | 59.9% | 14.5% | +45.4% | 6.1% | 21.8% |

#### Overview

Solano County has been a Democratic stronghold in presidential and congressional elections, with Californians Richard Nixon (in 1972) and Ronald Reagan (in 1980 and 1984) being the only Republicans to win the county since 1928. However, the northern area of Solano County including Vacaville and Dixon have begun shifting right as evidenced by the 2022 midterms, voters in Congressional District 4 favoring the Republican candidate 50.3% to 49.7%.
United States presidential election results for Solano County, California :
| Year | Republican | Republican | Democratic | Democratic | Third party(ies) | Third party(ies) |
| Year | No. | % | No. | % | No. | % |
| 2024 | 70,345 | 36.91% | 113,997 | 59.82% | 6,231 | 3.27% |
| 2020 | 69,306 | 33.51% | 131,639 | 63.65% | 5,886 | 2.85% |
| 2016 | 51,920 | 30.88% | 102,360 | 60.87% | 13,870 | 8.25% |
| 2012 | 52,092 | 34.08% | 96,783 | 63.32% | 3,965 | 2.59% |
| 2008 | 56,035 | 34.68% | 102,095 | 63.18% | 3,458 | 2.14% |
| 2004 | 62,301 | 41.86% | 85,096 | 57.17% | 1,440 | 0.97% |
| 2000 | 51,604 | 39.17% | 75,116 | 57.02% | 5,015 | 3.81% |
| 1996 | 40,742 | 34.74% | 64,644 | 55.12% | 11,893 | 10.14% |
| 1992 | 38,883 | 29.43% | 64,320 | 48.69% | 28,908 | 21.88% |
| 1988 | 50,314 | 47.43% | 54,344 | 51.23% | 1,430 | 1.35% |
| 1984 | 51,678 | 54.51% | 41,982 | 44.29% | 1,138 | 1.20% |
| 1980 | 40,919 | 50.72% | 30,952 | 38.37% | 8,805 | 10.91% |
| 1976 | 26,136 | 42.40% | 33,682 | 54.64% | 1,826 | 2.96% |
| 1972 | 31,314 | 54.02% | 24,766 | 42.73% | 1,885 | 3.25% |
| 1968 | 17,683 | 34.71% | 27,271 | 53.52% | 5,998 | 11.77% |
| 1964 | 15,263 | 30.38% | 34,930 | 69.53% | 47 | 0.09% |
| 1960 | 18,751 | 40.88% | 26,977 | 58.81% | 141 | 0.31% |
| 1956 | 17,865 | 41.68% | 24,903 | 58.10% | 95 | 0.22% |
| 1952 | 19,369 | 42.37% | 26,130 | 57.16% | 216 | 0.47% |
| 1948 | 12,345 | 33.71% | 23,257 | 63.50% | 1,022 | 2.79% |
| 1944 | 10,361 | 29.77% | 24,335 | 69.93% | 105 | 0.30% |
| 1940 | 6,081 | 28.51% | 15,054 | 70.58% | 193 | 0.90% |
| 1936 | 3,603 | 20.89% | 13,459 | 78.05% | 182 | 1.06% |
| 1932 | 4,382 | 30.30% | 9,712 | 67.16% | 367 | 2.54% |
| 1928 | 7,061 | 52.32% | 6,278 | 46.51% | 158 | 1.17% |
| 1924 | 4,782 | 48.00% | 957 | 9.61% | 4,223 | 42.39% |
| 1920 | 7,102 | 64.77% | 2,954 | 26.94% | 909 | 8.29% |
| 1916 | 3,536 | 36.35% | 5,678 | 58.37% | 514 | 5.28% |
| 1912 | 40 | 0.50% | 3,650 | 45.66% | 4,303 | 53.83% |
| 1908 | 3,115 | 54.72% | 2,033 | 35.71% | 545 | 9.57% |
| 1904 | 3,176 | 61.37% | 1,555 | 30.05% | 444 | 8.58% |
| 1900 | 3,114 | 55.36% | 2,262 | 40.21% | 249 | 4.43% |
| 1896 | 2,702 | 53.19% | 2,284 | 44.96% | 94 | 1.85% |
| 1892 | 2,403 | 49.21% | 2,174 | 44.52% | 306 | 6.27% |
| 1888 | 2,231 | 49.67% | 2,158 | 48.04% | 103 | 2.29% |
| 1884 | 2,382 | 53.61% | 1,977 | 44.50% | 84 | 1.89% |
| 1880 | 1,963 | 49.80% | 1,959 | 49.70% | 20 | 0.51% |
Solano County is split between California's 4th, 7th and 8th congressional districts, represented by Mike Thompson (D–St. Helena), Doris Matsui (D–Sacramento) and John Garamendi (D–Walnut Grove) respectively.
In the California State Assembly, Solano County is split between the 4th Assembly District, represented by Democrat Cecilia Aguiar-Curry, and the 11th Assembly District, represented by Democrat Lori Wilson. In the California State Senate, it is in the 3rd Senate District, represented by Democrat Christopher Cabaldon.
On November 4, 2008, Solano County voted 55.82% in favor of Proposition 8, which amended the California Constitution to ban same-sex marriages. It was the only Bay Area county to approve the initiative. In the 2008 presidential election that day, Barack Obama carried the county by a 28.5% margin over John McCain, a larger margin than statewide (24%).
According to the California Secretary of State, as of February 10, 2019, Solano County has 236,028 registered voters. Of those, 106,452 (45.1%) are registered Democrats, 50,006 (21.2%) are registered Republicans, and 66,558 (28.2%) have declined to state a political party. Democrats hold voter-registration advantages in all incorporated cities and towns in Solano County. However, Republicans lead in registration in the unincorporated communities of the county (40%-35%), making Solano the only county in the Bay Area where Republicans out-number Democrats in unincorporated communities. The Democrats' largest registration advantage in Solano is in the city of Vallejo, wherein there are only 8,242 Republicans (14.6%) out of 56,313 total voters compared to 33,753 Democrats (59.9%) and 12,157 voters who have declined to state a political party (21.6%).

## Communities
### Cities

* Benicia
* Dixon
* Fairfield (county seat)
* Rio Vista
* Suisun City
* Vacaville
* Vallejo
* People line up at the gate to the Solano County Fair in Vallejo, California
* A building on the Solano County Fairgrounds

### Census-designated places

* Allendale
* Elmira
* Green Valley
* Hartley

### Other unincorporated communities

* Bahia
* Batavia
* Birds Landing
* Bucktown
* Collinsville
* Cordelia
* Denverton
* Maine Prairie
* Mankas Corner
* Rockville
* Scandia

### Population ranking

The population ranking of the following table is based on the 2020 census of Solano County.
† county seat
| Rank | Settlement | Municipal type | Population (2020 census) |
| 1 | Vallejo | City | 126,090 |
| 2 | † Fairfield | City | 119,881 |
| 3 | Vacaville | City | 102,386 |
| 4 | Suisun City | City | 29,518 |
| 5 | Benicia | City | 27,131 |
| 6 | Dixon | City | 18,988 |
| 7 | Rio Vista | City | 10,005 |
| 8 | Hartley | CDP | 2,430 |
| 9 | Green Valley | CDP | 1,654 |
| 10 | Allendale | CDP | 1,651 |
| 11 | Elmira | CDP | 193 |

## Miscellania

* In 1985 Humphrey the humpback whale strayed off his migration route and ended up in Shag Slough north of Rio Vista. Rescuers from the Marine Mammal Center and other volunteers dismantled a county bridge before being able to turn him around in the narrow slough.