Cache Creek (Sacramento River tributary)
Cache Creek is an 87-mile-long stream in Lake and Yolo counties, California. Cache Creek starts at the outlet of Clear Lake, it has two main tributaries: North Fork. The Capay Diversion Dam, west of Capay, diverts water for distribution throughout Yolo County using a network of canals. At the end of the Capay Valley, near Esparto, Cache Creek runs east into Sacramento Valley, ending in a settling basin east of Woodland, the overflow of which runs into the Sacramento River through a flood control canal. In addition to the recreational use of Clear Lake and Indian Valley Reservoir there are numerous trail-heads and campgrounds, including the Bear Valley wildflower hotspot. Bear Creek and Cache Creek run in a scenic canyon along State Route 16 in Colusa and Yolo county, including the Cache Creek Regional Park. Cache Creek provides white-water rafting, both in the spring when it is flooded, through the summer using the agricultural water flow; the entire area south of Route 20 and west of Route 16 is a wildlife preserve, hosting two herds of Tule Elk.
The name of the water body comes from Hudson's Bay Company trappers who cached their furs along the Sacramento River and smaller tributaries, one of which became known to them as Cache Creek. One of their camps, recognized by early settlers as French Camp, was situated in a grove of oaks on the north bank of Cache Creek one mile east of the present town of Yolo, California. Cache Creek was known to the Hudson's Bay Company trappers as Rivière la Cache. Cache Creek was temporarily blocked north of Rumsey by a landslide caused by the 1906 San Francisco earthquake: Our Rumsey correspondent mentions the fall of Cache Creek as a result of an earthquake shock Tuesday night; the water has continued to fall some since that date and in some places it is dry. Upon investigation by the officials of the Water Company it was found that a landslide had dammed the Creek near the Leonard ranch in Lake county.... The creek subsequently broke through. Cache Creek has two main tributaries: North Fork, Bear Creek.
Cache Creek begins at the south-east end of Clear Lake, flowing east to the dam which now controls the level of Clear Lake. The North Fork begins in Lake County in the Mendocino National Forest north of Upper Lake, it flows east, where it is joined by Bartlett Creek, is dammed by the Indian Valley Reservoir. It flows south along New Long Valley Road, turns east along State Route 20, which it crosses at the Cache Creek Recreation Area. Cache Creek runs north-east from the dam, behind Perkins Creek Ridge and over The Jams Waterfall before joining the North Fork about 2 miles east of the bridge over Route 20. Bear Creek starts in Bear Valley and runs south through a canyon until it meets Route 20, it runs east in parallel with Route 20 for a few miles, turns south, again cutting through a canyon following State Route 16 in Colusa and Yolo Counties. Meanwhile, Cache Creek cuts south-east between Cache Creek Ridge and Little Blue Ridge, joining Bear Creek at Route 16 near the junction of Lake and Yolo counties.
The combined Cache Creek continues in the canyon. The Capay Diversion Dam, west of Capay, diverts water for distribution throughout Yolo County using a 175-mile network of canals. At the end of the Capay Valley near Esparto Cache Creek runs east into Sacramento Valley, ending in a settling basin east of Woodland. If the Sacramento river is not in flood any overflow runs into the Tule Canal,continues as Prospect Slough and enters the Sacramento River at Cache Slough. If the Sacramento IS in flood the overflow from the settling basin is swept into the Yolo Bypass and Sacramento Bypass flood control system, emerging directly at Cache Slough. Water rights and flooding protection have been in dispute between Yolo and Lake Counties since the late 19th century; the Yolo County Flood Control & Water Conservation District has "an 1855 priority right to divert the natural flow of Cache Creek, 1912 priority right to store waters in Clear Lake to elevation 7.56 feet Rumsey Gauge for release and beneficial use."
Various decrees attempt to ensure a balance between the needs of the two counties, although high-water conditions can cause temporary disagreements. Under the Solano Decree Yolo holds appropriative rights for up to 150,000 acre feet per year from Clear Lake, all the water from the Indian Valley dam; the Cache Creek Dam on the South Fork of Cache Creek, five miles downstream from Clear Lake, was built to increase Clear Lake's capacity and to regulate outflow for downstream users of Cache Creek water. The dam was modified to include a 3 MW hydroelectric plant; the stream has a small capacity, less than a quarter of the amount the dam is able to release. There is a rock ledge a mile and a half downstream of Clear Lake, called the Grigsby Riffle, near the bridge on State Route 53; this ledge restricts the amount of water. The limited capacity of the stream means that it takes a long time to drain excess flow from Clear Lake, increasing the chance of flooding around the lake; the bottleneck is seen as a backup to prevent flooding downstream and Yolo County is prohibited from increasing the capacity of the channel by the Gopcevic and Bemmerly Decrees.
The Indian Valley dam on the North Fork of Cache Creek forms Indian Valley Reservoir. The dam's primary purpose is water storage for irrigation, but a 3
Central Valley (California)
The Central Valley is a flat valley that dominates the geographical center of the U. S. state of California. It is 40 to 60 miles wide and stretches 450 miles from north-northwest to south-southeast, inland from and parallel to the Pacific Ocean coast, it covers 18,000 square miles, about 11% of California's total land area. The valley is bounded by the Sierra Nevada to the Coast Ranges to the west, it is California's single most productive agricultural region and one of the most productive in the world, providing more than half of the fruits and nuts grown in the United States. More than 7 million acres of the valley are irrigated via an extensive system of reservoirs and canals; the valley has many major cities, including the state capital Sacramento. The Central Valley watershed comprises over a third of California, it consists of three main drainage systems: the Sacramento Valley in the north, which receives well over 20 inches of rain annually. The Sacramento and San Joaquin river systems drain their respective valleys and meet to form the Sacramento–San Joaquin River Delta, a large expanse of interconnected canals, stream beds, sloughs and peat islands.
The delta empties into the San Francisco Bay, ultimately flows into the Pacific. The waters of the Tulare Basin never flow to the ocean, though they are connected by man-made canals to the San Joaquin and could drain there again if they were to rise high enough; the valley encompasses all or parts of 18 Northern California counties: Butte, Glenn, Kings, Merced, San Joaquin, Shasta, Stanislaus, Tehama, Yuba and the Southern California county of Kern. The Central Valley is known to residents as "the Valley." Older names include "the Great Valley," a name still seen in scientific references, "Golden Empire," a booster name, still referred to by some organizations. The Central Valley is outlined by the Cascade, Sierra Nevada, Tehachapi mountain ranges on the east, the California Coast Ranges and San Francisco Bay on the west; the broad valley floor is carpeted by vast agricultural regions, dotted with numerous population centers. Subregions and their counties associated with the valley include: North Sacramento Valley Sacramento Metro North San Joaquin South San Joaquin There are four main population centers in the Central Valley, each equidistant from the next, from south to north: Bakersfield, Fresno and Redding.
While there are many communities large and small between these cities, these four cities act as hubs for regional commerce and transportation. About 6.5 million people live in the Central Valley today, it is the fastest growing region in California. There are 12 Metropolitan Statistical Areas and 1 Micropolitan Statistical Area in the Central Valley. Below, they are listed by μSA population; the largest city is the state capital Sacramento, followed by Fresno. The following metropolitan and micropolitan statistical areas listed from largest to smallest: The flatness of the valley floor contrasts with the rugged hills or gentle mountains that are typical of most of California's terrain; the valley is thought to have originated below sea level as an offshore area depressed by subduction of the Farallon Plate into a trench further offshore. The San Joaquin Fault is a notable seismic feature of the Central Valley; the valley was enclosed by the uplift of the Coast Ranges, with its original outlet into Monterey Bay.
Faulting moved the Coast Ranges, a new outlet developed near what is now San Francisco Bay. Over the millennia, the valley was filled by the sediments of these same ranges, as well as the rising Sierra Nevada to the east; the one notable exception to the flat valley floor is Sutter Buttes, the remnants of an extinct volcano just to the northwest of Yuba City, 44 miles north of Sacramento. Another significant geologic feature of the Central Valley lies hidden beneath the delta; the Stockton Arch is an upwarping of the crust beneath the valley sediments that extends southwest to northeast across the valley. The Central Valley lies within the California Trough physiographic section, part of the larger Pacific Border province, which in turn is part of the Pacific Mountain System; the "Central Valley grassland" is the Nearctic temperate and subtropical grasslands and shrub lands ecoregion, once a diverse grassland containing areas of desert grassland, savanna, riverside woodland, several types of seasonal vernal pools, large lakes such as now-dry Tulare Lake, Buena Vista Lake and Kern Lake.
However, much of the Central Valley environment
Point Reyes is a prominent cape and popular Northern California tourist destination on the Pacific coast. It is located in Marin County 30 miles west-northwest of San Francisco; the term is applied to the Point Reyes Peninsula, the region bounded by Tomales Bay on the northeast and Bolinas Lagoon on the southeast. The headland is protected as part of Point Reyes National Seashore; the cape protects Drakes Bay on its southern side. The headland is drained by Drakes Estero. Drakes Bay and Drake's Estero are named after English seafarer Sir Francis Drake who hauled his ship, the Golden Hinde, up onto the beach for repairs in June 1579. Inverness Ridge runs along the peninsula's northwest-southeast spine, with forested peaks around 430 meters. West of the ridge, the land flattens out and the vegetation turns to scrub; the Mount Vision fire in 1995 burned part of Inverness Ridge. Point Reyes lends its name to the town of Point Reyes Station; the point may once have been known as Lobes Lighthouse by the sailors of clipper ships on the meat trade..
Point Reyes' first inhabitants, the Coast Miwok, lived on the land for thousands of years. They left evidence of well over a hundred encampments on the peninsula, with a population estimated to have been nearly 3,000. Seasonal hunters and gatherers, they were nourished by fish, clams and crab, in addition to the deer, bear, mud hen and small game they hunted with spears and bows. Although they did not cultivate the land, the Coast Miwok utilized a variety of different plants growing at Point Reyes. In particular, acorns served as a staple, as they could be stored in dry granaries to provide sustenance when food was less plentiful. Although the Coast Miwok periodically interacted with European explorers, they continued their peaceful existence until late in the 18th century when the Spanish built Mission San Rafael and padres began journeying to Point Reyes to recruit them to move to the mission. While attempting to convert them, these padres disrupted their traditional way of life and introduced diseases that brought untimely deaths, fewer births, increasing infant mortality rates.
In 1992, Coast Miwok descendants established the Federated Indians of Graton Rancheria, in December 2000, legislation passed granting the tribe federal recognition. Today, the tribe boasts 500 members, who enjoy a rebirth of traditional customs and ceremonies held in Kule Loklo, "Valley of the Bear", a replica Miwok village in Point Reyes National Seashore. On 13 November 1542, Spanish explorer Juan Rodríguez Cabrillo sighted and named "Cabo de Pinos", but missed the entrance to San Francisco Bay, a lapse that mariners would repeat for the next two centuries and more, due to the fog that characterizes the area; the Spanish explorer Sebastián Vizcaíno named the land Punto de los Reyes when his ship, the Capitana anchored in Drakes Bay on the Day of the Three Kings on January 6, 1603. Although early explorers and Spanish trading galleons journeying between the Philippines and Acapulco passed by Point Reyes, some anchoring it is the landing by Sir Francis Drake that dominates discussion of this era of Point Reyes early history.
The exact location of his landing, significant as the first European landing in Northern California, has sparked countless hours of spirited debate spanning four centuries. Some experts believe, that he landed somewhere near the area on June 17, 1579 and proclaimed it Nova Albion. Most as validated by a National Historic Landmark designation, the precise place of Drake's landing is Drake's Cove at Point Reyes National Seashore. Although the exact location of Sir Francis Drake's 1579 anchorage at Point Reyes is still being debated, his chaplain's observations about the areas inhabitants suggest the landing occurred near a Coast Miwok settlement; these notes describe the genial welcome Drake and his men received, complete with ceremony and gifts, as well as the landscape and wildlife, included commentary about fog which obscures the peninsula during the summer months. Rumors of Drake's discovery of a safe harbor on the California coast intrigued the Spanish, their trade between the Philippines and Mexico was booming, they were seeking safe harbors along their route.
Many believe that Drake's discovery of such a harbor inspired the Spanish to order Sebastian Rodriguez Cermeno, a Portuguese captain trading for Spain, to survey the California coast on his journey to Mexico from the Philippines in 1595. Commanding San Agustin, a Manila galleon laden with a luxury cargo of Chinese silks and Ming porcelain bound for Acapulco, Cermeno endured both the first of hundreds of documented shipwrecks at Point Reyes, as well as one of the most amazing journeys to safety. Among the crew were Filipino mariners. Struggling with a decrepit laden ship and a tired crew, Cermeno explored the California coast anchoring near the Point Reyes inlet now called Drakes Estero. Within a few days, a November storm beached the ship where it listed and was relentlessly pounded by the furious surf, it soon broke apart, killing several men and dumping the precious cargo, some of, collected and used by the local Coast Miwok inhabitants. Cermeno salvaged a small, open launch, likened to a large canoe, loaded it with the 70 surviving crew members to begin the long journey home.
After a grueling two-month voyage, remembered as a remarkable feat of seamanship and all crew arrived safely in Acapulco in January 1596. Despite his
San Jose, California
San Jose the City of San José, is an economic and political center of Silicon Valley, the largest city in Northern California. With an estimated 2017 population of 1,035,317, it is the third-most populous city in California and the tenth-most populous in United States. Located in the center of the Santa Clara Valley, on the southern shore of San Francisco Bay, San Jose covers an area of 179.97 square miles. San Jose is the county seat of Santa Clara County, the most affluent county in California and one of the most affluent counties in the United States. San Jose is the most populous city in both the San Francisco Bay Area and the San Jose-San Francisco-Oakland Combined Statistical Area, which contain 7.7 million and 8.7 million people respectively. San Jose is a global city, notable as a center of innovation, for its affluence, Mediterranean climate, high cost of living. San Jose's location within the booming high tech industry, as a cultural and economic center has earned the city the nickname "Capital of Silicon Valley".
San Jose is one of the wealthiest major cities in the United States and the world, has the third highest GDP per capita in the world, according to the Brookings Institution. The San Jose Metropolitan Area has the most millionaires and the most billionaires in the United States per capita. With a median home price of $1,085,000, San Jose has the most expensive housing market in the country and the fifth most expensive housing market in the world, according to the 2017 Demographia International Housing Affordability Survey. Major global tech companies including Cisco Systems, eBay, Adobe Systems, PayPal, Samsung, Hewlett Packard Enterprise, Western Digital maintain their headquarters in San Jose, in the center of Silicon Valley. Before the arrival of the Spanish, the area around San Jose was inhabited by the Tamien nation of the Ohlone peoples of California. San Jose was founded on November 29, 1777, as the Pueblo de San José de Guadalupe, the first city founded in the Californias, it became a part of Mexico in 1821 after the Mexican War of Independence.
Following the American Conquest of California during the Mexican–American War, the territory was ceded to the United States in 1848. After California achieved statehood two years San Jose became the state's first capital. Following World War II, San Jose experienced an economic boom, with a rapid population growth and aggressive annexation of nearby cities and communities carried out in the 1950s and 1960s; the rapid growth of the high-technology and electronics industries further accelerated the transition from an agricultural center to an urbanized metropolitan area. Results of the 1990 U. S. Census indicated that San Jose had surpassed San Francisco as the most populous city in Northern California. By the 1990s, San Jose and the rest of Silicon Valley had become the global center for the high tech and internet industries, making it California's fastest-growing economy; the Santa Clara Valley has been home to the Tamyen group of the Ohlone people since around 4,000 BCE. The Tamyen spoke Tamyen language of the Ohlone language family.
With the Spanish colonization of California, the majority of the Tamyen came to inhabit Mission Santa Clara de Asís and Mission San José. California was claimed as part of the Spanish Empire in 1542, when explorer Juan Rodríguez Cabrillo charted the Californian coast. During this time and Baja California were administered together as Province of the California. For nearly 200 years, the Californias were sparsely populated and ignored by the government of the Viceroyalty of New Spain in Mexico City. Only in 1769 was Northern California surveyed by Spanish authorities, with the Portolá Expedition. In 1776, the Californias were included as part of the Captaincy General of the Provincias Internas, a large administrative division created by José de Gálvez, Spanish Minister of the Indies, in order to provide greater autonomy for the Spanish Empire's populated and ungoverned borderlands; that year, King Carlos III of Spain approved an expedition by Juan Bautista de Anza to survey the San Francisco Bay Area, in order to choose the sites for two future settlements and their accompanying mission.
First he chose the site for a military settlement in San Francisco, for the Royal Presidio of San Francisco, Mission San Francisco de Asís. On his way back to Mexico from San Francisco, de Anza chose the sites in Santa Clara Valley for a civilian settlement, San Jose, on the eastern bank of the Guadalupe River, a mission on its western bank, Mission Santa Clara de Asís. San Jose was founded as California's first civilian settlement on November 29, 1777, as the Pueblo de San José de Guadalupe by José Joaquín Moraga, under orders of Antonio María de Bucareli y Ursúa, Viceroy of New Spain. San Jose served as a strategic settlement along El Camino Real, connecting the military fortifications at the Monterey Presidio and the San Francisco Presidio, as well as the California mission network. In 1791, due to the severe flooding which characterized the pueblo, San Jose's settlement was moved a mile south, centered on the Pueblo Plaza. In 1800, due to the growing population in the northern part of the Californias, Diego de Borica, Governor of the Californias split the province into two parts: Alta California, which would become a U.
S. state, Baja California, which would become two Mexican states. San Jose became part of the First M
Schoenoplectus acutus, called tule, common tule, hardstem tule, tule rush, hardstem bulrush, or viscid bulrush, is a giant species of sedge in the plant family Cyperaceae, native to freshwater marshes all over North America. The common name derives from the Nāhuatl word tōllin, was first applied by the early settlers from New Spain who recognized the marsh plants in the Central Valley of California as similar to those in the marshes around Mexico City. Tules once lined the shores of Tulare Lake, California the largest freshwater lake in the western United States, until it was drained by land speculators in the 20th century; the expression "out in the tules" is still common, deriving from the dialect of old Californian families and means "where no one would want to live", with a touch of irony. The phrase is comparable to "out in the boondocks". Schoenoplectus acutus has a thick, rounded green stem growing to 1 to 3 m tall, with long, grasslike leaves, radially symmetrical, pale brownish flowers.
Tules at shorelines play an important ecological role, helping to buffer against wind and water forces, thereby allowing the establishment of other types of plants and reducing erosion. Tules are sometimes cleared from waterways using herbicides; when erosion occurs, tule rhizomes are replanted in strategic areas. The two varieties are: Schoenoplectus acutus var. acutus – northern and eastern North America Schoenoplectus acutus var. occidentalis – southwestern North America Dyed and woven, tules are used to make baskets, mats, clothing, duck decoys, boats by Native American groups. Before the Salish got horses for bison hunting, they lived in tents covered with sewed mats of tule. At least two tribes, the Wanapum and the Pomo people, constructed tule houses as as the 1950s and still do for special occasions. Bay Miwok, Coast Miwok, Ohlone peoples used the tule in the manufacture of canoes or balsas, for transportation across the San Francisco Bay and using the marine and wetland resources. Northern groups of Chumash used the tule in the manufacture of canoes rather than the sewn-plank tomol used by Chumash and used them to gather marine harvests.
The Paiutes named a neighboring tribe the Si-Te-Cah in their language. The young sprouts and shoots can be eaten raw and the rhizomes and unripe flower heads can be boiled as vegetables. One of the few Pomo survivors of the Bloody Island Massacre in Northern California, a 6-year-old girl named Ni'ka, or Lucy Moore, evaded the United States Cavalry by hiding behind the tule reeds in the bloodied water, her descendants have since formed the Lucy Moore Foundation to work for better relations between the Pomo and residents of California. It is so common in wetlands in California, several places in the state were named for it, including Tulare. Tule Lake includes Tule Lake National Wildlife Refuge, it was the site of an internment camp for Japanese Americans during World War II, imprisoning 18,700 people at its peak. The town of Tulelake is northeast of the lake. California has a Tule River; the Tule Desert is located in Nevada. Nevada has Tule Springs. California's dense, ground-hugging tule fog is named for the plant, as are the tule elk and tule perch.
The giant garter snake was closely associated with tule marshes in California's Central Valley. Munz, Philip A. A California Flora. Berkeley, CA: University of California Press, 1973, copyright 1959 Munz, Philip A. A California Flora: Supplement. Berkeley, CA: University of California Press, 1976 Jones, Terry L. and Klar, Kathryn California prehistory: colonization and complexity, Walnut Creek, CA: Altamira Press, 2007 C. Michael Hogan Morro Creek, published by Megalithic Portal, ed. Andy Burnham Tule Boat Photo Gallery Tule reed canoe, launched on Lake Merced, San Francisco Tule reed canoe, Modoc Swall, Corinne. Tule reed boat workbook: a voyage of adventure. Kentfield, CA: Mother Lode Musical Theatre, Watershed Preservation Network. Archived from the original on 2011-07-27
Mount Hamilton (California)
Mount Hamilton is a mountain in California's Diablo Range, in Santa Clara County, California. Mount Hamilton, at 4,265 feet is a mountain overlooking Santa Clara Valley and is the site of Lick Observatory, the World's first permanently occupied mountain-topobservatory; the asteroid 452 Hamiltonia, discovered in 1899, is named after the mountain. Golden eagle. On clear days, Mount Tamalpais, the Santa Cruz Mountains, Monterey Bay, the Monterey Peninsula, Yosemite National Park are visible from the summit of the mountain. On August 26, 1861, while working for Josiah D. Whitney on the first California Geological Survey, William H. Brewer invited local San Jose preacher Laurentine Hamilton to join his company on a trek to a nearby summit. Nearing completion of their journey, Hamilton, in good humor, bounded for the summit ahead of the rest of the men and claimed his stake. In fact, Brewer suggested the mountain be named after Hamilton, only after Whitney declined to have the mountain named after him.
The Spanish name for Mt. Hamilton was the Sierra de Santa Isabel and the highest point was known as Mount Isabel instead of Mount Hamilton. William Henry Brewer and his fellow geologist, Charles F. Hoffmann, did not know it had a name, named it Mt. Hamilton, although they did place Isabel Valley on their map to the east; the "Hotel Santa Ysabel" was built on the road up the mountain in 1885 on Smith Creek. When in 1895, the USGS realized that the peak two miles southeast of Mt. Hamilton was as tall, they named it Mt. Isabel; these mountains are high enough to receive snowfall in the winter up to a dozen times. When a cold, wet storm comes in from the Gulf of Alaska or Canada, Mt. Hamilton and the surrounding peaks get significant snowfall. In February 2001, 30 inches of snow fell, in March 2006, the peak was left with over a foot of snow in one night; the National Weather Service has had a cooperative weather station on the summit of Mount Hamilton since the time that the Lick Observatory opened.
It has provided a glimpse of the extreme weather conditions that occur on the Diablo Range in the winter months. January is the coldest month on Mount Hamilton with an average high of 49.4 °F and an average low of 37.5 °F. The warmest month is July with an average high of 78.2 °F and an average low of 63.1 °F. Due to frequent thermal inversions during the summer, it is warmer on Mount Hamilton than in San Jose; the record high temperature of 103 °F was on August 5, 1978. The record low temperature of 7 °F was on December 21, 1990; the average days with highs of 90 °F or higher is 4.3 days. The average days with lows of 32 °F or lower is 50.6 days. Annual precipitation averages 23.73 inches. Measurable rainfall occurs on an average of 71.9 days each year. The most rainfall in a month was 12.13 inches in February 1998. The maximum rainfall in 24 hours was 6.87 inches on December 23, 1955. Annual snowfall averages 10 inches; the maximum snowfall in a year was 59.0 inches in 1955. The maximum snowfall in a month was 38.1 inches in February 2019.
The 24-hour maximum snowfall of 14.0 inches occurred on February 18, 1990. The deepest daily snow depth was 18 inches in March 1976. Measurable snow has been recorded in every month from November through June. Mount Hamilton is one summit along a mile-long ridge. Other than Hamilton, peaks along the ridge have astronomical names, such as Kepler; the highest peak on the ridge is Copernicus Peak, with elevation 4,360+ ft. Copernicus Peak is located 0.8 miles to the northeast from Mount Hamilton, is the highest point in Santa Clara County. Unlike Mount Hamilton's limited prominence, Copernicus Peak has a prominence of 3,080 ft; the sinuous 19-mile Mt. Hamilton Road is used by bicyclists and motorcyclists. Built in 1875–76 in anticipation of the observatory, the need to carry materials and equipment up the mountain in horse-drawn wagons, the grade exceeds 6.5 percent. The road rises over 4,000 feet in three long climbs from San Jose to the mountain top. On a clear day at the summit it is possible to see the Sierra Nevada.
Cyclists use the road because of the long but not overly challenging nature of the climb, sparse vehicular traffic over most of its length, the views of San Jose and the Santa Clara Valley below. There is an annual cycling challenge climb in April. Thanksgiving draws hundreds of cyclists and is the final climb in the annual Low-Key Hillclimb Series which attracts some of the region's best climbers; the bicycle ride is just over 19 miles from the Alum Rock Road junction. The upward trek is interrupted by two descents, first into Grant Ranch County Park, again to cross Smith Creek. Quimby Road offers a shorter way from San Jose to Grant Ranch, but is steeper; the main observatory building has water, a few vending machines, an opportunity to warm up on a cold day. If the time is right, there are free 15-minute guided tours of the Great Lick refracting telescope, the gift shop may be open. Much of the foothill slopes of Mount Hamilton is underlain by Miocene age sandstone of the Briones formation: this bedrock is locally soft and weathered in the upper few feet, but grades locally to hard at depth.
Depth to groundwater on these foothill areas of Mount Hamilton is 240
Habitat destruction is the process by which natural habitat becomes incapable of supporting its native species. In this process, the organisms that used the site are displaced or destroyed, reducing biodiversity. Habitat destruction by human activity is for the purpose of harvesting natural resources for industrial production and urbanization. Clearing habitats for agriculture is the principal cause of habitat destruction. Other important causes of habitat destruction include mining, logging and urban sprawl. Habitat destruction is ranked as the primary cause of species extinction worldwide, it is a process of natural environmental change that may be caused by habitat fragmentation, geological processes, climate change or by human activities such as the introduction of invasive species, ecosystem nutrient depletion, other human activities. The terms habitat loss and habitat reduction are used in a wider sense, including loss of habitat from other factors, such as water and noise pollution. In the simplest term, when a habitat is destroyed, the plants and other organisms that occupied the habitat have a reduced carrying capacity so that populations decline and extinction becomes more likely.
The greatest threat to organisms and biodiversity is the process of habitat loss. Temple found that 82% of endangered bird species were threatened by habitat loss. Most amphibian species are threatened by habitat loss, some species are now only breeding in modified habitat. Endemic organisms with limited ranges are most affected by habitat destruction because these organisms are not found anywhere else within the world, thus have less chance of recovering. Many endemic organisms have specific requirements for their survival that can only be found within a certain ecosystem, resulting in their extinction. Extinction may take place long after the destruction of habitat, a phenomenon known as extinction debt. Habitat destruction can decrease the range of certain organism populations; this can result in the reduction of genetic diversity and the production of infertile youths, as these organisms would have a higher possibility of mating with related organisms within their population, or different species.
One of the most famous examples is the impact upon China's giant panda, once found across the nation. Now it is only found in fragmented and isolated regions in the southwest of the country, as a result of widespread deforestation in the 20th century. Biodiversity hotspots are chiefly tropical regions that feature high concentrations of endemic species and, when all hotspots are combined, may contain over half of the world’s terrestrial species; these hotspots are suffering from habitat destruction. Most of the natural habitat on islands and in areas of high human population density has been destroyed. Islands suffering extreme habitat destruction include New Zealand, the Philippines, Japan. South and East Asia — China, Malaysia and Japan — and many areas in West Africa have dense human populations that allow little room for natural habitat. Marine areas close to populated coastal cities face degradation of their coral reefs or other marine habitat; these areas include the eastern coasts of Asia and Africa, northern coasts of South America, the Caribbean Sea and its associated islands.
Regions of unsustainable agriculture or unstable governments, which may go hand-in-hand experience high rates of habitat destruction. Central America, Sub-Saharan Africa, the Amazonian tropical rainforest areas of South America are the main regions with unsustainable agricultural practices and/or government mismanagement. Areas of high agricultural output tend to have the highest extent of habitat destruction. In the U. S. less than 25 % of native vegetation remains in many parts of the Midwest. Only 15% of land area remains unmodified by human activities in all of Europe. Tropical rainforests have received most of the attention concerning the destruction of habitat. From the 16 million square kilometers of tropical rainforest habitat that existed worldwide, less than 9 million square kilometers remain today; the current rate of deforestation is 160,000 square kilometers per year, which equates to a loss of 1% of original forest habitat each year. Other forest ecosystems have suffered as more destruction as tropical rainforests.
Farming and logging have disturbed at least 94% of temperate broadleaf forests. Tropical deciduous dry forests are easier to clear and burn and are more suitable for agriculture and cattle ranching than tropical rainforests. Plains and desert areas have been degraded to a lesser extent. Only 10-20% of the world's drylands, which include temperate grasslands and shrublands, deciduous forests, have been somewhat degraded, but included in that 10-20% of land is the 9 million square kilometers of seasonally dry-lands that humans have converted to deserts through the process of desertification. The tallgrass prairies of North America, on the other hand, have less than 3% of natural habitat remaining that has not been converted to farmland. Wetlands and marine areas have endured high levels of habitat destruction. More than 50% of wetlands in the U. S. have been destroyed in just the last 200 years. Between 60% and 70% of European wetlands have been destroyed. In the United Kingdom, there has been an i