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County Data for Contra Costa County, California

Contra Costa County (Spanish for "opposite coast") is a primarily suburban county in the San Francisco Bay Area of the U. S. state of California. As of the 2006, the US Census Bureau estimated it had a population of 1,024,319. The county seat is Martinez.



In prehistoric times, particularly the Miocene epoch, portions of the landforms now in the area (then marshy and grassy savanna) were populated by a wide range of now extinct mammals, known in modern times by the fossil remains excavated in the southern part of the county. In the northern part of the county, significant coal and sand deposits were formed in even earlier geologic eras. Other areas of the county have ridges exposing ancient but intact (not fossilized) seashells, embedded in sandstone layers alternating with limestone. Layers of volcanic ash ejected from geologically recent but now extinct volcanos, compacted and now tilted by compressive forces, may be seen at the site of some road excavations. This county is an agglomeration of several distinct geologic terranes, as is most of the greater San Francisco Bay Area, which is one of the most geologically complex regions in the world. The great local mountain Mount Diablo has been formed and continues to be elevated by compressive forces resulting from the action of plate tectonics and at its upper reaches presents ancient seabed rocks scraped from distant oceanic sedimentation locations and accumulated and lifted by these great forces. Younger deposits at middle altitudes include pillow lavas, the product of undersea volcanic eruptions.

Native American period

There is an extensive but little recorded human pre-European invasion history in this area, with the present county containing portions of regions populated by a number of native American tribes. The earliest definitively established occupation by modern man (Homo sapiens) appears to have occurred six to ten thousand years ago. However, there may have been human presence far earlier, at least as far as non–settling populations are concerned. The known settled populations were hunter-gatherer societies that had no knowledge of metals and that produced utilitarian crafts for everyday use (especially woven reed baskets) of the highest quality and with graphic embellishments of great aesthetic appeal. Extensive trading from tribe to tribe transferred exotic materials such as obsidian (useful for the making of arrowheads) throughout the region from far distant Californian tribes. Unlike the nomadic native American of the Great Plains it appears that these tribes did not incorporate warfare into their culture but were instead generally cooperative. Within these cultures the concept of individual or collective land ownership was nonexistent. Early European settlers in the region, however, did not record much about the culture of the natives. Most of what is known culturally comes from preserved contemporaneous and excavated artifacts and from inter-generational knowledge passed down through northerly outlying tribes of the larger region.

Spanish colonial

Early interaction of these Native Americans with Europeans came with the Spanish colonization via the establishment of missions in this area, with the missions in San Jose, Sonoma, and San Francisco and particularly the establishment of the Presidio of San Francisco (a military establishment) in 1776. Although there were no missions established within this county, Spanish influence here was direct and extensive, through the establishment of land grants from the King of Spain to favored settlers.

Mexican land grants

In 1821 Mexico gained independence from Spain. While little changed in ranchero life, the Mexican War of Independence resulted in the secularization of the missions with the re-distribution of their lands, and a new system of land grants under the Mexican Federal Law of 1824. Mission lands extended throughout the Bay Area, including portions of Contra Costa County. Between 1836 and 1846, during the era when California was a province of independent Mexico, the following 15 land grants were made in Contra Costa County.

The smallest unit was one square league, or about seven square miles, or , maximum to one individual was eleven leagues, or , including no more than of irrigable land. Rough surveying was based on a map, or diseño, measured by streams, shorelines, and/or horseman who marked it with rope and stakes. Lands outside Rancho grants were designated ‘el sobrante,' as in surplus or excess, and considered common lands. The law required the construction of a house within a year. Fences were not required and were forbidden where they might interfere with roads or trails. Locally a large family required roughly 2000 head of cattle and two square leagues of land (fourteen square miles) to live comfortably. Foreign entrepreneurs came to the area in order to provide goods that Mexico couldn’t, and trading ships were taxed.

  • Rancho Canada de los Vaqueros was granted to Francisco Alviso, Antonio Higuera, and Manuel Miranda ( confirmed in 1889 to heirs of Robert Livermore).
  • Two ranchos, both called Rancho San Ramon, were granted by the Mexican government in the San Ramon Valley. In 1833, Bartolome Pacheco (southern San Ramon Valley) and Mariano Castro (northern San Ramon Valley) shared the two square league Rancho San Ramon. Jose Maria Amador was granted a four square league Rancho San Ramon in 1834.
  • In 1834 Rancho Monte del Diablo (present day Concord, California) was confirmed with to Salvio Pacheco (born July 15, 1793, died 1876). The Pacheco family settled at the Rancho in 1846 (between the Pacheco shipping port townsite and Clayton area, and including much of Lime Ridge). The boundary lines were designated with stone markers. Clayton was later located on sobrante lands just east of Rancho Monte del Diablo (Mount Diablo).
  • In 1834, Rancho Arroyo de Las Nueces y Bolbones aka Rancho San Miguel (present day Walnut Creek), was granted to Juana Sanchez de Pacheco, in recognition of the service of Corporal Miguel Pacheco 37 years earlier (confirmed 1853, patented to heirs 1866); the grant was for two leagues, but drawn free hand on the diseño/map, and reading "two leagues, more or less" as indicated in the diseño, but actually including and confirmed for nearly four leagues or nearly , but only were ever shown as having once belonged to Juana Sanchez.
  • 'Meganos' means 'sand dunes. ' A "paraje que llaman los Méganos" 'place called the sand dunes' (with a variant spelling) is mentioned in Durán’s diary on May 24, 1817. Two Los Meganos Ranchos were granted, later differentiated as Rancho Los Meganos (1835, three leagues or at least ) in what is now the Brentwood area, to Jose Noriega then acquired by John Marsh; and Rancho Los Medanos (to Jose Antonio Mesa and Jose Miguel Garcia, Pittsburg area, dated November 26, 1839).
  • Bear Flag Republic and the statehood of California

    The exclusive land ownership by Hispanics would soon end. This change began with the Bear Flag Revolt in 1846 when a few settlers from the United States declared a republic in June 1846 and were fighting under the U. S. flag by July 1846. Following the Mexican-American War of 1846-48, California was controlled by U. S. settlers organized under the California Battalion and the U. S. Navy by 1846 and annexed and paid for by the U. S. in 1848. The large and rapid population gain due to the California gold rush gave California enough population to be admitted to the Union in 1850.

    Contra Costa's creation and division

    Contra Costa County was one of the original counties of California, created in 1850 at the time of statehood. The county was originally to be called Mt. Diablo County, but the name was changed prior to incorporation as a county. The county's Spanish language name means opposite coast, because of its location opposite San Francisco, in an easterly direction, on San Francisco Bay. Southern portions of the county's territory, including all of the bayside portions opposite San Francisco and northern portions of Santa Clara County, were given up to form Alameda County effective March 25, 1853.

    The land titles in Contra Costa County may be traced to multiple subdivisions of a few original land grants. The grantee's family names live on in a few city and town names such as ''Martinez'', ''Pacheco'' and ''Moraga'' and in the names of streets, residential subdivisions, and business parks. A few mansions from the more prosperous farms have been preserved as museums and cultural centers and one of the more rustic examples has been preserved as a working demonstration ranch, Borges Ranch.


    During World War II, Richmond hosted one of the two Bay Area sites of Kaiser Shipyards and wartime pilots were trained at what is now Concord/Buchanan Field Airport. Additionally, a large Naval Weapons Depot and munitions ship loading facilities at Port Chicago remain active to this day, but with the inland storage facilities recently declared surplus, extensive redevelopment is being planned for this last large central-county tract. The loading docks were the site of a devastating explosion in 1944. Port Chicago was bought out and demolished by the Federal Government to form a safety zone near the Naval Weapons Station loading docks. At one time the Atlas Powder Company (subsequently closed)produced gunpowder and dynamite. The site of the former Atlas Powder Company is located at Point Pinole Regional Shoreline, part of the East Bay Regional Parks District.

    Early postwar period

    With the postwar baby boom and the desire for suburban living, large tract housing developers would purchase large central county farmsteads and develop them with roads, utilities and housing. Once mostly rural walnut orchards and cattle ranches, the area was first developed as low cost, large lot suburbs, with a typical low cost home being placed on a "quarter acre" (1,000 m²) lot — actually a little less at 10,000 square feet (930 m²). Some of the expansion of these suburban areas was clearly attributable to white flight from decaying areas of Alameda County and the consolidated city-county of San Francisco, but much was due to the postwar baby boom of the era creating demand for three and four bedroom houses with large yards which were unaffordable or unavailable in the established bayside cities.

    Later postwar period (1955 - 1970)

    A number of large companies have followed their employees to the suburbs, filling large business parks. The establishment of a large, prosperous population in turn fostered the development of large shopping centers and created demand for an extensive supporting infrastructure including roads, schools, libraries, police, firefighting, water, sewage, and flood control.

    Modern period

    The establishment of BART, the modernization of Highway 24, and the addition of a third Caldecott Tunnel all served to reenforce the demographic and economic trends in Diablo area, with cities such as Walnut Creek becoming edge cities.

    The central county cities have in turn spawned their own suburbs within the county, extending east along the county's estuarine north shore; with the older development areas of Bay Point and Pittsburg being augmented by extensive development in Antioch, Oakley, and Brentwood.

    Some of the inner suburbs accessible from highway 24 (such as Rockridge in north Oakland, Alameda County), in turn have become gentrified, offering easier access and shorter commutes to businesses that remained or established in San Francisco, particularly financial organizations.

    Political geography

    According to the U. S. Census Bureau, the county has a total area of 802 square miles (2,078 km²), of which, 720 square miles (1,865 km²) of it is land and 82 square miles (213 km²) of it (10. 25%) is water.

    It is bounded on the south and west by Alameda County; on the northwest San Francisco Bay (San Francisco and Marin Counties); on the North by San Pablo Bay, the Carquinez Strait, and Suisun Bay (Solano and Sacramento Counties); and on the east by the San Joaquin River (San Joaquin County).

    Physical geography

    Contra Costa County's physical geography is dominated by the bayside alluvial plain, the Oakland Hills-Berkeley Hills, and Mount Diablo, an isolated 3,849-foot (1,173 m) upthrust peak at the north end of the Diablo Range of hills. The summit of Mount Diablo is the origin of the Mount Diablo Meridian and Base Line, on which the surveys of much of California and western Nevada are based.

    The Hayward Fault Zone runs through the western portion of the county, from Kensington to Richmond. The Calaveras Fault runs in the south-central portion of the county, from Alamo to San Ramon. The Concord Fault runs through part of Concord and Pacheco, and the Clayton-Marsh Creek-Greenville Fault runs from Clayton at its north end to near Livermore. These slip-strike earthquake faults and the Diablo thrust fault near Danville are all considered capable of significantly destructive earthquakes and many lesser related faults are present in the area that cross critical infrastructure such as water, natural gas, and petroleum product pipelines, roads, highways, railroads, and BART rail transit.

    Cities and towns

    Martinez Court House, California

    West County

    Incorporated places

  • El Cerrito
  • Hercules
  • Pinole
  • Richmond
  • San Pablo
  • Unincorporated places

  • Bayview-Montalvin
  • Crockett
  • East Richmond Heights
  • El Sobrante
  • Kensington
  • North Richmond
  • Port Costa
  • Rodeo
  • Rollingwood
  • Tara Hills
  • Central County

    Incorporated places

  • Clayton
  • Concord
  • Danville
  • Lafayette
  • Martinez
  • Moraga
  • Orinda
  • Pleasant Hill
  • San Ramon
  • Walnut Creek
  • Unincorporated places

  • Alamo
  • Blackhawk-Camino Tassajara
  • Canyon
  • Clyde
  • Diablo
  • Mountain View
  • Pacheco
  • Vine Hill
  • Waldon
  • East County

    Incorporated places

  • Antioch
  • Brentwood
  • Oakley
  • Pittsburg
  • Unincorporated places

  • Bay Point
  • Bethel Island
  • Byron
  • Discovery Bay
  • Knightsen
  • Other named regions and developments

  • Saranap - an unincorporated residential area between Walnut Creek and Lafayette, centered around the site of a (now-gone) inter-urban train station, comprising much of ZIP Code 94595.
  • Rossmoor - a senior development incorporated into Walnut Creek (not to be confused with the Southern California Rossmoor).
  • Adjacent counties

  • Alameda County - south (all the southern border)
  • Marin County - west (via the Richmond-San Rafael Bridge and San Pablo and San Francisco Bays)
  • Solano County - north (via the Carquinez Bridges and Benicia-Martinez Bridge and the Carquinez Strait, Grizzly Bay, Suisun Bay, and Sacramento/San Joaquin River delta and mouth)
  • Sacramento County - northeast (in the delta Islands and via the Antioch Bridge)
  • San Joaquin County - east (across the San Joaquin River and many islands and sloughs, most of the eastern border)
  • San Francisco County - southwest (on Red Rock Island and on the San Francisco Bay)
  • National protected areas

  • Antioch Dunes National Wildlife Refuge
  • Eugene O'Neill National Historic Site
  • John Muir National Historic Site
  • Rosie the Riveter/World War II Home Front National Historical Park
  • Landmark of Mount Diablo

    The most notable natural landmark in the county is Mount Diablo, at the northerly end of the Diablo Range. Mount Diablo and its neighboring North Peak are the centerpiece of Mt. Diablo State Park (MDSP), created legislatively in 1921 and rededicated in 1931 after land acquisitions had been completed. At the time this comprised a very small portion of the mountain.

    In the 1960s the open space of the mountain was threatened with suburban development expanding from the surrounding valleys. In 1971, when MDSP included , the non-profit organization Save Mount Diablo, was formed and open space preservation accelerated. MDSP was the first of twenty-nine Diablo area parks and preserves created around the peaks, today totaling more than . These Diablo public lands stretch southeast and include the Concord Naval Weapons Station, Shell Ridge Open Space and Lime Ridge Open Spaces near Walnut Creek, to the State Park, and east to the Los Vaqueros Reservoir watershed and four surrounding East Bay Regional Park District preserves, including Morgan Territory Regional Preserve, Brushy Peak Regional Preserve, Vasco Caves Regional Preserve, and Round Valley Regional Preserves. The new Cowell Ranch State Park, and Black Diamond Mines Regional Preserve, are among the open spaces stretching back to the north. In this way the open spaces controlled by cities, the East Bay Regional Park District, Mount Diablo State Park, and various regional preserves now adjoin and protect most of the elevated regions of the mountain.

    The name Mount Diablo is said to originate from an incident involving Spanish soldiers who christened a thicket ‘Monte del Diablo’ when natives they were pursuing apparently disappeared in the thicket. Anglo settlers later misunderstood the use of the word ‘monte’ (which can mean ‘mountain’, or ‘thicket’), and fastened the name on the most obvious local landmark.

    Transportation infrastructure

    Prior to 1903 most travel to central Contra Costa County was by boat or rail to Martinez on the northern waterfront and from there to the industrial areas east along the waterfront as well as farming regions to the south.

    In 1903 the first tunnel through the Oakland hills (now Old Tunnel Road) was built, principally as a means of bringing hay by horse, mule, or ox-drawn wagons from central and eastern agricultural areas to feed the draft animals that provided the power to public and private transportation in the East Bay at the time. The tunnel exited in the hills high above the crossroads of Orinda with the road continuing on to Lafayette, Walnut Creek, and Danville. The road was just wide enough for one car in each direction, and had no shoulders.

    In 1937 the two-bore Caldecott Tunnel for road vehicles was completed, making interior Contra Costa much more accessible. After World War II the tunnels allowed waves of development to proceed, oriented toward Oakland rather than the northern shoreline, and the northern shoreline cities began to decline. The tunnel has since been augmented with an additional bore, with the central bore reversed in direction to accommodate commute traffic. Owing to extensive reverse commuting and general increases in traffic, a fourth bore is being planned.

    Major highways

  • alt= Interstate 80
  • alt= Interstate 580
  • alt= Interstate 680
  • alt= State Route 4
  • alt= State Route 24
  • alt= State Route 160
  • alt= State Route 242
  • alt= San Pablo Avenue – formerly alt= U. S. Route 40
  • Mass transit

  • Amtrak runs its San Joaquins line to Southern California and Capital Corridor line to Sacramento and San José through stations in Richmond, Martinez, and Antioch-Pittsburg.
  • BART High speed commuter rail system, which functions as the Bay Area's metro system.
  • AC Transit provides local service in West County and in Orinda, in addition to western Alameda County, Transbay commuter services to San Francisco, BRT lines and the bulk of All Nighter service for the East Bay.
  • County Connection provides local service in Central County and connecting services to Dublin and Pittsburg.
  • Tri-Delta Transit provides local bus service in East County and connecting regional services to Martinez, Livermore, and Stockton.
  • WestCAT provides local bus service in northern West County with connecting service to BART and transbay service to the city (San Francisco).
  • Golden Gate Transit provides connecting transbay service between San Rafael and Richmond and El Cerrito del Norte BART stations via the Richmond-San Rafael Bridge.
  • Vallejo Transit and Fairfield and Suisun Transit provide regional feeder service to El Cerrito del Norte BART from Solano County.
  • Benicia Transit provides commuter service between the Vallejo Ferry Terminal and BART in Concord through Benicia in Solano County.
  • Airports

    The county also has two airports that are not currently providing passenger service:

  • Buchanan Field Airport, located in Concord
  • Byron Airport, located two miles (3 km) south of Byron
  • Railroads

    The western termini of several original transcontinental railroad routes have been located in Oakland, in Alameda County, Including Union Pacific, Southern Pacific, and Santa Fe railroads. From Oakland, there are two primary routes east:

  • The former Southern Pacific (originally Central Pacific Railroad) line north through Richmond, closely hugging the San Pablo Bay coastline to Martinez, where it crosses Suisun Bay on a drawbridge before proceeding to Sacramento and the crossing of the Sierra Nevada via Donner Pass.
  • The former Western Pacific Railroad line which runs east through Niles Canyon, Livermore and over Altamont Pass en route to in a north-easterly direction to Sacramento and the Feather River canyon/Beckwourth Pass crossing of the Sierra Nevada.
  • Formed in 1909, the Oakland Antioch Railway was renamed the Oakland Antioch & Eastern Railway in 1911. It extended through a tunnel in the Oakland Hills, from Oakland to Walnut Creek, Concord and on to Bay Point.

    The current owner of the Santa Fe Rairoad's assets, BNSF Railway has the terminus of its transcontinental route in Richmond. Originally built by the San Francisco and San Joaquin Valley Railroad in 1896, the line was purchased by the Atchison, Topeka and Santa Fe Railway shortly thereafter. The line leaves Richmond through industrial and residential parts of West County before striking due east through Franklin Canyon and Martinez on its way to Stockton, Bakersfield and Barstow.

    These railroads spurred the development of industry in the county throughout the late 19th and early 20th centuries, particularly driving development of the Standard Oil (now Chevron) refinery and port complex in Richmond.

    There were a large number of short lines in the county between the late 19th century and the early 20th century. The rights of way of a number of these railroads also served as utility rights of way, particularly for water service, and so were preserved, and in the late 20th century enhanced as walking, jogging, and bicycle riding trails in the central portion of the county.

    Alternative Commute Infrastructure

    Contra Costa County also provides alternative commute options for those without cars or who choose to commute in an environmentally friendly manner. The Bay Area Rapid Transit BART train network stops in many cities in the County, and the County Connection bus service serves areas not immediately adjacent to BART stations. In addition, the local transportation demand management organization 511 Contra Costa offers services to County residents who wish to switch from single occupancy vehicle driving to greener modes.



    The great rancheros of the Spanish period were divided and sold for agricultural uses, with intensively irrigated farming made possible in some areas by the development of canals that brought water from the eastern riverside portions of the county to the central portion. Other areas could used the more limited water available from local creeks and from wells. Orchards dominated where such water was available, while other, seasonally dry areas were used for cattle ranching. In central parts of the county walnuts were an especially attractive orchard crop, using the thin-shelled English Walnut branches grafted to the hardy and disease-resistant American Walnut root stock. In the Moraga region, pears dominated, and many old (but untended) roadside trees are still picked seasonally by passers by. In eastern county, stone fruit, especially cherries, is still grown commercially, with seasonal opportunities for people to pick their own fruit for a modest fee.

    Commuter railroads

    The development of commuter railroads proceeded together with the subdivision of farms into parcels. In some cases, such as the development of Saranap, the same developer controlled both the railroad (Sacramento Northern) and the development. These early suburbanization developments were an extension of the earlier development of trolley car suburbs in what are now considered the highly urban environments of the near East Bay.

    Irrigation canals

    The Contra Costa Canal, a concrete-lined and fenced irrigation canal still makes a loop through central county and provided industrial and agricultural grade water to farms and industry. While no longer used for extensive irrigation, it is still possible for adjoining landowners (now large suburban lot owners) to obtain pumping permits. Most of this water is destined for the heavy industry near Martinez. As with the railroad rights of way there is now an extensive public trail system along these canals.

    Heavy industry

    Owing to its extensive waterfront on San Francisco, San Pablo, and Suisun bays the northwestern and northern segments have long been sites for heavy industry, including a number of still active oil refineries (particularly Chevron in Richmond and Tosco - formerly Shell Oil - in Martinez), chemical plants (Dow Chemical) and a once substantial integrated steel plant, Posco Steel (formerly United States Steel), now reduced to secondary production of strip sheet and wire. The San Joaquin River forms a continuation of the northern boundary turns southward to form the eastern boundary of the county. Some substantial Sacramento-San Joaquin Delta "islands" (actually leveed former marshes) are included in this corner of the county.


    West County

    The West County is the area near or on San Francisco and San Pablo bays. The housing stock in the region was extensively developed after the great San Francisco Earthquake of 1906. Much of the housing stock in these areas is becoming quite expensive. As an alternative to moving to either the expensive central county, or the too-distant East County, this area is becoming gentrified, with a mix of races and income levels — a character actively sought by some housing purchasers. The downside of this is a corresponding lack of affordable housing for those in lower paying service jobs — a problem endemic throughout the region. There has recently been a housing boom or tract housing in Richmond and also in the Hercules areas. These gentrifying areas are the most diverse in Contra Costa County.

    Central county

    The central part of the county is a valley traversed by Interstate 680 and Highway 24. The towns east of the hills, on or near Highway 24 and their surrounding areas (Lafayette, Moraga and Orinda) are collectively known as Lamorinda. The major central county cities along Interstate 680 are Martinez, Concord, Pleasant Hill, Walnut Creek, Danville, San Ramon, and unincorporated Alamo. Owing to the high quality of its public schools (due largely to both demographics and added support from prosperous parents), this area has become a magnet for well–off families with children. During the real estate boom, housing prices were driven to astounding levels. From 2007, home prices in the region have seen substantial decreases and the affordability rate has risen. During the real estate boom, the high price of homes and scarcity of land resulted in many speculators purchasing older, smaller homes and partially or completely tearing them down in order to construct larger homes.

    In this way the central county region has become a mix of older suburbs, newer developments, small lot "infill" developments, and extensive shopping areas.

    East County

    Lower cost modern tract developments continue along Suisun Bay and into rural "East County" - new "bedroom" communities" to serve the now "edge cities". This results in some incredibly long and slow commutes for some county residents, as roadbuilding is unable to keep pace with the development patterns. Some political control has been established to restrict the development somewhat, with "urban limit lines" now established, but yet to prove their long term effectiveness. The building of new housing in the hot inland areas of California is straining the ability of power providers during hot weather, with peak power requirements statewide reaching levels not expected until 2010 in a 2006 late July heat wave.

    Urban decay at the fringes

    Other cities in the once heavily industrialized northwestern and western waterfront areas such as Richmond have fallen on harder times, with Richmond having difficulty balancing its school budget. This may be arguably attributed to a side effect of Proposition 13: it applies also to large industrial and merchandising companies, which have seen their share of property taxes (the bulk of which is used to support local schools) decline severely. As housing prices have not kept pace with the more central and outlying regions and housing turnover is also low (which establishes a new tax base for the parcel), the school districts are having difficulty obtaining proper funding. A lack of the availability of the kind of community support available in the more prosperous regions also contributes to the problem, with higher income residents of some of these declining or gentrifying areas sending their children to private schooling, creating a self reinforcing decline in the public schools.

    County budget problems

    Two forces have combined to create county budget problems peaking in 2008. First, (over a thirty year period) rather than compensate police, medical, and firefighting personnel directly, very favorable health and retirement benefits were granted without proper actuarial examination, leading to unexpected (yet predictable) high costs as personnel age and ultimately retire with continued "first class" health and retirement benefits. Second, the collapse of the "housing bubble" has enabled purchasers of distressed properties (many of which are owned by banks and other mortgage holders) to petition for lower property assessments, in many cases reducing by half the revenue to the county for specific parcels. Continuing downturns in employment prospects (particularly in new housing construction) have further increased the needs for various social services. These deficits and demands, combined with a lack of support from a similarly stressed California state government and the United States Federal government have combined to require unpleasant choices to be made by county supervisors and county service providers in the allocation of limited resources in a time of increasing demand.

    Technical innovators

    In the 1970s and 80s many small and innovative technical firms were started in this county, most of which are no longer present, having either failed, been absorbed into larger corporations, or having outgrown their original location are now elsewhere in the Bay Area.

    Corporate headquarters

    During the 1980s and early 1990s, many corporations that were formerly housed in the more central metropolitan area followed their employees by moving to large suburban and edge city office areas and office parks.

    A number of large corporations now have headquarters in large developments along what is called the 680 corridor, that segment of Interstate Highway 680 that extends from Concord in the north to San Ramon in the south, continuing into inland Alameda County from Dublin to Pleasanton.

    By the early 1990s, more square footage of office space had been built in the 680 corridor than in San Francisco's Financial District.


    There are currently political fights over the potential redevelopment of the county seat (Martinez), with long term residents and many elsewhere in the county concerned that it will lose its remaining small-town charm and utility in an effort to become more like the county's major recreational shopping center of Walnut Creek.

    The inland portions of the Concord Naval Weapons Station have been declared surplus by the Federal government and this area is expected to provide what is likely the last opportunity to plan and build city-sized development within the central county. This area will become a portion of the city of Concord and it is expected that development will be confined to the lower and flatter portions of the depot, with the remainder becoming a substantial addition to the county's open space. As much of the land to be developed is largely relatively flat grassland space, with the most prominent structures ammunition bunkers that will be removed, the planning of future uses of the property will be largely unconstrained by previous uses.


    Contra Costa County Library is the county's library system.


    The city of Concord is served by the daily newspaper, the Contra Costa Times published by the Bay Area News Group-East Bay (part of the Media News Group, Denver, Colorado), with offices in Walnut Creek. The paper was originally a paper run and owned by the Lesher family. Since the death of Dean Lesher in 1993, the paper has had several owners. The publisher also issues weekly local papers, such as the Concord Transcript which is the local paper for Concord and nearby Clayton.


    As of the census of 2000, there were 948,816 people, 344,129 households, and 242,266 families residing in the county. The population density was 1,318 people per square mile (509/km²). There were 354,577 housing units at an average density of 492 per square mile (190/km²). The racial makeup of the county was:

  • 65. 50% White
  • 9. 36% Black or African American
  • 0. 61% Native American
  • 10. 96% Asian
  • 0. 37% Pacific Islander
  • 8. 06% from other races
  • 5. 13% from two or more races.
  • 17. 68% of the population were Hispanic or Latino of any race. 9. 0% were of German, 7. 7% Irish, 7. 3% English and 6. 5% Italian ancestry according to Census 2000. 74. 1% spoke English, 13. 1% Spanish, 2. 6% Tagalog and 1. 8% Chinese or Mandarin as their first language.

    By 2005 53. 2% of Contra Costa County's population were non-Hispanic whites. African-Americans made up 9. 6% of the population, while Asians constituted 13. 1% of it. Latinos were now 21. 1% of the county population.

    In 2000 there were 344,129 households out of which 35. 4% had children under the age of 18 living with them, 54. 5% were married couples living together, 11. 5% had a female householder with no husband present, and 29. 6% were non-families. 22. 9% of all households were made up of individuals and 8. 00% had someone living alone who was 65 years of age or older. The average household size was 2. 72 and the average family size was 3. 23.

    In the county the population was spread out with:

  • 26. 5% under the age of 18
  • 7. 7% from 18 to 24
  • 30. 6% from 25 to 44
  • 23. 9% from 45 to 64
  • 11. 3% who were 65 years of age or older.
  • The median age was 36 years. For every 100 females there were 95. 4 males. For every 100 females age 18 and over, there were 92. 2 males.

    The median income for a household in the county was $63,675, and the median income for a family was $73,039 (these figures had risen to $75,483 and $87,435 respectively as of a 2007


    Males had a median income of $52,670 versus $38,630 for females. The per capita income for the county was $30,615. About 5. 4% of families and 7. 6% of the population were below the poverty line, including 9. 8% of those under age 18 and 6. 0% of those age 65 or over.


    Contra Costa County has become a Democratic stronghold, with even wealthy cities like Orinda and Walnut Creek voting Democratic in recent elections. The last Republican to win a majority in the county was Ronald Reagan in 1984. With the exceptions of Danville and Clayton, every city, town, and the unincorporated areas of Contra Costa County have more registered Democrats than Republicans.

    {| align="right" border="2" cellpadding="4" cellspacing="0" style="margin: 1em 1em 1em 0; border: 1px #aaa solid; border-collapse: collapse; font-size: 95%;"

    |+ Presidential election results

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    ! Year

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    ! GOP


    |align="center" bgcolor="#f0f0ff"|2008

    |align="center" bgcolor="#f0f0ff"|67. 9% 297,353

    |align="center" bgcolor="#fff3f3"|30. 5% 133,272


    |align="center" bgcolor="#f0f0ff"|2004

    |align="center" bgcolor="#f0f0ff"|62. 3% 257,254

    |align="center" bgcolor="#fff3f3"|36. 5% 150,608


    |align="center" bgcolor="#f0f0ff"|2000

    |align="center" bgcolor="#f0f0ff"|58. 8% 224,338

    |align="center" bgcolor="#fff3f3"|37. 1% 141,373


    |align="center" bgcolor="#f0f0ff"|1996

    |align="center" bgcolor="#f0f0ff"|55. 7% 196,512

    |align="center" bgcolor="#fff3f3"|35. 2% 123,954


    |align="center" bgcolor="#f0f0ff"|1992

    |align="center" bgcolor="#f0f0ff"|50. 9% 194,960

    |align="center" bgcolor="#fff3f3"|29. 5% 112,965


    |align="center" bgcolor="#f0f0ff"|1988

    |align="center" bgcolor="#f0f0ff"|51. 1% 169,411

    |align="center" bgcolor="#fff3f3"|47. 9% 158,652


    |align="center" bgcolor="#fff3f3"|1984

    |align="center" bgcolor="#f0f0ff"|44. 6% 140,994

    |align="center" bgcolor="#fff3f3"|54. 5% 172,331


    |align="center" bgcolor="#fff3f3"|1980

    |align="center" bgcolor="#f0f0ff"|37. 3% 107,398

    |align="center" bgcolor="#fff3f3"|50. 1% 144,112


    |align="center" bgcolor="#fff3f3"|1976

    |align="center" bgcolor="#f0f0ff"|48. 2% 123,742

    |align="center" bgcolor="#fff3f3"|49. 4% 126,598


    |align="center" bgcolor="#fff3f3"|1972

    |align="center" bgcolor="#f0f0ff"|43. 5% 111,718

    |align="center" bgcolor="#fff3f3"|54. 1% 139,044


    |align="center" bgcolor="#f0f0ff"|1968

    |align="center" bgcolor="#f0f0ff"|46. 4% 101,668

    |align="center" bgcolor="#fff3f3"|44. 5% 97,486


    |align="center" bgcolor="#f0f0ff"|1964

    |align="center" bgcolor="#f0f0ff"|63. 4% 113,071

    |align="center" bgcolor="#fff3f3"|36. 5% 65,011


    |align="center" bgcolor="#f0f0ff"|1960

    |align="center" bgcolor="#f0f0ff"|52. 9% 93,622

    |align="center" bgcolor="#fff3f3"|46. 8% 82,922



    Contra Costa is part of California's 7th, 10th, and 11th congressional districts. All three are held by Democrats: George Miller, John Garamendi, and Jerry McNerney, respectively. In the State Assembly, parts of the 11th, 14th, and 15th districts are in the county. The 11th, 14th, and 15th districts are represented by Democrats Tom Torlakson, Nancy Skinner, and Joan Buchanan, respectively. In the State Senate, all of the 7th district and part of the 9th district are in the county. Both districts are represented by Democrats, the 7th by Mark DeSaulnier and the 9th by Loni Hancock.

    On November 4, 2008 Contra Costa County voted 55. 4 % against Proposition 8 which amended the California Constitution to ban same-sex marriages.

    Museums and historic sites

  • Blackhawk Museum http://www. blackhawkmuseum. org/ (This site also contains a paleontological museum of the University of California, Berkeley)
  • John Marsh House http://www. johnmarshhouse. com/marsh_hs. htm
  • Eugene O'Neill National Historic Site
  • John Muir National Historic Site
  • Lindsay Wildlife Museum
  • Don Francisco Galindo House
  • Don Salvio Pacheco Adobe http://www. conhistsoc. org/WalkingTour/16. html
  • Martinez Adobe
  • San Ramon Valley Museum http://www. museumsrv. org
  • Borges Ranch
  • Parks and related places

  • Briones Regional Park http://www. ebparks. org/parks/briones. htm*
  • Diablo Foothills http://www. ebparks. org/parks/diablo. htm
  • Howe Homestead Park http://www. ci. walnut-creek. ca. us/openspace/oshowe_homestead. htm
  • Mount Diablo State Park
  • Las Trampas Regional Wilderness http://www. ebparks. org/parks/lastram. htm*
  • Shell Ridge Open Space http://www. ci. walnut-creek. ca. us/openspace/shell_ridge. htm
  • Lime Ridge Open Space http://www. ci. walnut-creek. ca. us/openspace/oslime_ridge. htm
  • San Pablo Recreation Area (San Pablo Dam Reservoir) http://www. ebmud. com/services/recreation/east_bay/san_pablo/default. htm
  • Sugarloaf Open Space http://www. ci. walnut-creek. ca. us/openspace/sugarloafpage. htm
  • Acalanes Open Space http://www. ci. walnut-creek. ca. us/openspace/osacalanes. htm
  • Point Isabel Regional Shoreline in Richmond is the largest dog park in the country.
  • Adjoining or nearby these parks are lands of the East Bay Municipal Utility District. These require special annual permits for hiking, bicycle riding and horse riding, available for a small fee. At least one member of a party traversing these areas must have such a permit.
  • Trails

  • Iron Horse Regional Trail
  • California State Riding and Hiking Trail http://www. ebparks. org/parks/calrhktr. htm
  • Contra Costa Canal Regional Trail http://www. ebparks. org/parks/canaltr. htm
  • Delta de Anza Regional Trailhttp://www. ebparks. org/parks/deanza. htm
  • Briones-Mount Diablo Regional Trail http://www. ebparks. org/parks/brdiotr. htm
  • Lafayette-Moraga Regional Trail http://www. ebparks. org/parks/canaltr. ht
  • Marsh Creek Trail http://www. ebparks. org/parks/marshtr. htm
  • Utilities

  • Central Contra Costa Sanitary District
  • California casino proposals

    Since 2003, four Indian gaming casinos have been proposed in Richmond and the surrounding area of West Contra Costa County.


  • Hilltop Mall to be built on a site.
  • Lytton Rancheria at Casino San Pablo from the Scotts Valley band of the Pomo tribe and have 2,500 (originally 5,000) slot machines.
  • Point Molate Casino Resort to have a luxury shopping mall, 1,100 room hotel/resort.
  • North Richmond to be located on a site and have a buffet.
  • Notes

    #For a collection of insightful observations of the Mexican provincial culture and trading practice (most notably in the acquisition of cattle hides for eastern U. S. shoe manufacturies) see portions of Two Years Before the Mast, a first person narative of a seaman's voyage to California starting in 1834.

    Land for sale in Contra Costa County, California

    This County information was provided courtesy of Wikipedia