Калифорния штатындағы Контра-Коста округі

County in California, United States

Contra Costa County (,/k//ɒ//n//t//r//ə// /'/k//ɒ//s//t//ə//audio=En us contra costa. ogg/; Contra Costa, Spanish for "Opposite Coast") is a county located in the U. S. state of California, in the East Bay of the San Francisco Bay Area. As of the 2020 United States Census, the population was 1,165,927. The county seat is Martinez. It occupies the northern portion of the East Bay region of the San Francisco Bay Area and is primarily suburban. The county's name refers to its position on the other side of the bay from San Francisco. Contra Costa County is included in the San Francisco–Oakland–Berkeley, CA Metropolitan Statistical Area.

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 volcanoes, 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.

There is an extensive but little recorded human history of pre European settlement 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 and other stone tools) 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.

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 a Presidio (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.

The exclusive land ownership in California by the approximate 9,000 Hispanics in California would soon end. John Marsh, owner of Rancho Los Meganos in Contra Costa County, had a lot to do with this. He sent letters to influential people in the eastern United States extolling the climate, soil, and potential for agriculture in California, with the deliberate purpose of encouraging Americans to immigrate to California and lead to its becoming part of the United States. He succeeded. His letters were published in newspapers throughout the East and started the first wagon trains rolling toward California. He also invited them to stay on his ranch until they could get settled, so the Rancho Los Meganos became the terminus of the California trail. This led to the Bear Flag Revolt in 1846 when about 30 settlers originally from the United States declared a republic in June 1846 and were enlisted and 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's Pacific Squadron. After some minor skirmishes, California was under U. S. control by January 1847 and formally annexed and paid for by the U. S. in 1848. By 1850, California's population of over 100,000 was rapidly growing due to the gold rush and the large amount of gold being exported east, which gave California enough clout to choose its own boundaries, write its own constitution, and be admitted to the Union as a free state in 1850 without going through territorial status as required for most other states. In 1850 California had a non Indian population of over 100,000. The number of Indians living in California in 1850 has been estimated to be from 60,000 to 100,000. By 1850 the Mission Indian populations had largely succumbed to disease and abuse and only numbered a few thousand. California's 1852 state Census gives 31,266 Indian residents, but this is an under count since there was little incentive and much difficulty in getting it more correct.

Contra Costa County was one of the original 27 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. In the 1860 United States Census, Contra Costa County had a population of 4,381.

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.

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 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 that were unaffordable or unavailable in the established bayside cities. A number of large companies 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. The establishment of the Bay Area Rapid Transit (BART) system, the modernization of Highway 24, and the addition of a fourth Caldecott Tunnel bore all served to reinforce the demographic and economic trends in the Diablo Valley area, with cities such as Walnut Creek and Concord 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. The effects of the housing value crash (2008–2011) varied widely throughout the county. Values of houses in prosperous areas with good schools declined only modestly in value, while houses recently built in outlying suburbs in the eastern part of the county experienced severe reductions in value, accelerated by high unemployment and consequent mortgage foreclosures, owner strategic walk aways, and the too rapid conversion of neighborhoods from owner occupancy to rentals. Home values rebounded as the economy recovered from the recession.

According to the U. S. Census Bureau, the county has a total area of 804 square miles (2,082 km2), of which 716 square miles (1,854 km2) is land and 88 square miles (228 km2) (11%) is water. Contra Costa County's physical geography is dominated by the bayside alluvial plain, the Oakland Hills–Berkeley Hills, several inland valleys, and Mount Diablo, an isolated 3,849 feet (1173 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 strike slip 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.

The most notable natural landmark in the county is the 3849 feet (1173 m) 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 park comprised a very small portion of the mountain. In the 1960s, suburban development expanding from the surrounding valleys began to threaten the open space of the mountain. In 1971, MDSP consisted of That year, concerned residents formed the non profit organization Save Mount Diablo to raise funds and awareness to protect more open space. In addition to encouraging acquisition by the state and local authorities, SMD started fundraising and acquiring properties to transfer to the park. MDSP was the first of twenty nine Diablo area parks and preserves that have been created around the peaks; today these preserves protect 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 Preserve. The new Marsh Creek State Park, formerly known as Cowell Ranch State Park, and Black Diamond Mines Regional Preserve, are among the open spaces that stretch to the north. 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 as Monte del Diablo when natives they were pursuing apparently disappeared into the thicket. Anglo settlers later misunderstood the use of the word 'monte' (which can mean 'mountain', or 'thicket'), and applied the name to the most obvious local landmark. According to the Contra Costa Times, in 2011, there were rumors that Contra Costa County was going to rename the mountain as "Mt. Ronald Reagan" or "Mt. Reagan", after the former US President and California governor. Residents have generated multiple petitions to change the name of the mountain, one in 2005 and another in 2011, but these were not successful.

Population, race, and income Total population 1,037,817   White 248,089 23.9% Per capita income $38,141 Median household income $79,135 Median family income $93,437

Across 30 years, two forces combined to create county budget problems, peaking in 2008. First, rather than compensate police, medical, and firefighting personnel directly, health and retirement benefits were granted without proper actuarial examination, leading to unexpected but predictable high costs as personnel aged and ultimately retired with continued "first class" health and retirement benefits. Second, the collapse of the "housing bubble" enabled purchasers of distressed properties — many of which were 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 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, required county supervisors and service providers to allocate limited resources in a time of increasing demand. The projected budget deficit was $45 million as of early 2011. Perhaps more significantly, the total unfunded liability for retiree benefits is $2.4 billion.

In the 1970s and 1980s, many small and innovative technical firms started in Contra Costa. Most of these are no longer present, either failing, being absorbed into larger corporations, or outgrowing their original location and moving elsewhere in the Bay Area.

By the early 1990s, 22 million square feet of office space had been built along 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. During the 1980s and early 1990s, many corporations that were formerly housed in the more central metropolitan area followed their employees by moving to these large suburban and edge city office areas and office parks.

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 planners expect 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. Much of the land to be developed is relatively flat grassland and the most prominent structures are ammunition bunkers that will be removed, so future uses of the property are largely unconstrained by previous uses.

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

Contra Costa County receives media from the rest of the Bay Area. The City of Concord is served by the daily newspaper, the East Bay 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. In December 2019, there was a flurry of reports from reliable sources including the Associated Press and the San Francisco Chronicle that the 161 year old Martinez News Gazette, one of the longest running newspapers in California, may have to cease publication. But as of late May 2020, the threatened cessation did not materialize and the newspaper appears to have weathered that storm. The newspaper did cease publication of a print edition effective April 2, 2020, but this was characterized as a temporary measure arising from a lack of advertising revenue. Since March 2020, this in turn arose as many local businesses were forced to suspended operations or even ceased to exist, when the area was under shelter in place regulations arising from COVID 19 pandemic. The newspaper plans to resume a full print edition when the local shelter in place restrictions are lifted.

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 County 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 a third bore, completed in 1964, and a fourth, completed in 2013.

Amtrak runs its San Joaquins line to Southern California and its Capitol Corridor line to Sacramento and San Jose through stations in Richmond, Martinez, and Antioch Pittsburg. BART, a high speed commuter rail system, functions as the Bay Area's metro system. eBART (East Contra Costa County BART extension) is designed to bring rapid transit services along the Highway 4 corridor. AC Transit provides local service in West County and in Orinda, in addition to western Alameda County, Transbay commuter services to San Francisco, bus rapid transit lines and the bulk of All Nighter service for the East Bay. County Connection provides local service in Central C. C. County and connecting services to Dublin and Pittsburg. Tri Delta Transit provides local bus service in East C. C. County and connecting regional services to Martinez, Livermore, and Stockton. WestCAT provides local bus service in northern West C. C. County with connecting service to BART and transbay service to the city (San Francisco). Golden Gate Transit provides connecting transbay service between Marin County 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.

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