Contra Costa

Contra Costa can refer to:

Mount Diablo

Mount Diablo is a mountain of the Diablo Range, in Contra Costa County of the eastern San Francisco Bay Area in Northern California. It is south of Clayton and northeast of Danville.

It is an isolated upthrust peak of 3,849 feet (1,173 m), visible from most of the San Francisco Bay Area. Mount Diablo appears from many angles to be a double pyramid and has many subsidiary peaks, the largest and closest of which is the other half of the double pyramid, North Peak, nearly as high in elevation at 3,557 feet (1,084 m) and about a mile northeast of the main summit.

Geography

The summit is accessible by foot, bicycle, or motor vehicle. Road access is via North Gate Road or South Gate Road.

Mount Diablo State Park

The peak is in Mount Diablo State Park, a state park of about 20,000 acres (8,000 ha). The park was the first public open space of a complex‍—‌according to Save Mount Diablo‍—‌now including 38 preserves, including nearby city open spaces, regional parks, watersheds, that are buffered in some areas with private lands protected with conservation easements. Preserved lands on and around Mount Diablo total more than 90,000 acres (36,000 ha). The day use fee per vehicle for the park is by entrance way: $6 via Macedo or Mitchellor, and $10 via Mount Diablo.

Contra Costa County, California

Contra Costa County is a county located in the U.S. state of California. As of the 2010 census, the population was 1,049,025. The county seat is Martinez. The name is Spanish for "opposite coast".

Contra Costa County is included in the San Francisco-Oakland-Hayward, CA Metropolitan Statistical Area. It occupies the northern portion of the East Bay region and is primarily suburban.

History

Pre-human

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.

California

California (ⁱ/ˌkælᵻˈfɔːrnjə/ KAL-ə-FORN-yə, /ˌkælᵻˈfɔːrniə/ KAL-ə-FAWR-nee-ə) is a state located on the West Coast of the United States. It is the most populous U.S. state, with 39 million people, and the third largest state by area (after Alaska and Texas). California is bordered by Oregon to the north, Nevada to the east, Arizona to the southeast, and the Mexican state of Baja California to the south. It contains the nation's second most populous census statistical area (Greater Los Angeles Area) and the fifth most populous (San Francisco Bay Area), and eight of the nation's 50 most populated cities (Los Angeles, San Diego, San Jose, San Francisco, Fresno, Sacramento, Long Beach, and Oakland). Sacramento has been the state capital since 1854.

What is now California was first settled by various Native American tribes before being explored by a number of European expeditions during the 16th and 17th centuries. It was then claimed by the Spanish Empire as part of Alta California in the larger territory of New Spain. Alta California became a part of Mexico in 1821 following its successful war for independence, but was ceded to the United States in 1848 after the Mexican–American War. The western portion of Alta California was organized as the State of California, which was admitted as the 31st state on September 9, 1850. The California Gold Rush starting in 1848 led to dramatic social and demographic change, with large-scale immigration from the east and abroad with an accompanying economic boom.

San Francisco Bay Area

The San Francisco Bay Area is a populous region surrounding the San Francisco and San Pablo estuaries in Northern California. The region encompasses the major cities and metropolitan areas of San Francisco, Oakland, and San Jose, along with smaller urban and rural areas. The Bay Area's nine counties are Alameda, Contra Costa, Marin, Napa, San Francisco, San Mateo, Santa Clara, Solano, and Sonoma. Home to approximately 7.44 million people, the nine-county Bay Area contains many cities, towns, airports, and associated regional, state, and national parks, connected by a network of roads, highways, railroads, bridges, tunnels and commuter rail. The combined statistical area of the region is the second-largest in California (after the Greater Los Angeles area), the fifth-largest in the United States, and the 43rd-largest urban area in the world.

The United States Office of Management and Budget (OMB) does not use the nine-county definition of the San Francisco Bay Area. The OMB has designated a more extensive 12-county Combined Statistical Area (CSA) titled the San Jose-San Francisco-Oakland, CA Combined Statistical Area which also includes the three counties of San Joaquin, Santa Cruz, and San Benito that do not border San Francisco Bay, but are economically tied to the nine counties that do.