Black Mountain (near Los Altos, California)
Encyclopedia
Black Mountain is a summit on Monte Bello Ridge in the Santa Cruz Mountains
of west Santa Clara County, California
, south of Los Altos
and west of Cupertino
. It is located on the border between Rancho San Antonio Open Space Preserve
and Monte Bello Open Space Preserve
, with the summit located in the former. Early Spanish explorers commonly named tree- or chaparral-covered summits which look black in the distance Loma Prieta, from the Spanish (loma-hill, prieta-dark).
The Spanish also called the middle portion of the Santa Cruz Mountains the Sierra Morena meaning (morena-brunette, sierra-mountain range), extending from Half Moon Bay Road (California State Route 92
) south to a gap at Lexington Reservoir
, and which includes a summit called Sierra Morena.
There are over 100 "Black Mountains" in California.
and the Peninsula
. There was a large dairy near what is now the Montebello Open Space Preserve's main parking area on Page Mill Road, and cattle freely grazed the slopes of Black Mountain. Ranch buildings dotted the landscape.
Oseo Perrone, a physician and immigrant from Mattarana, La Spezia Province, Italy, came to San Francisco in 1881, became interested in viticulture and purchased a large ranch at 2600 feet (792.5 m) on Black Mountain in 1885 where he, and then his nephew of the same name, began production of Montebello Winery (now Ridge Vineyards
) wine in 1892.
George Morell, founding publisher of the Palo Alto Times and a Trustee of Stanford University
, bought the Black Mountain Ranch on the mountain's summit in 1940. “Nature in the raw” is what led Mr. Morell to buy Black Mountain Ranch, according to his essay, “History of Black Mountain and Monte Bello Ridge,” written in 1959. Morell donated the land comprising the former Johnson, Winship, Morell ranches to Stanford University
.
In 1975, when the Black Mountain Ranch lands were acquired by the Midpeninsula Regional Open Space District
(MROSD) from Stanford, a commune of about 100 people, called "The Land", were evicted. The Land lived along the Canyon Trail from Page Mill Road to Indian Creek and built a variety of dwellings on platforms scattered amongst the oak woodlands and secluded canyons. A large ranch building was used as a central dining hall, and maintained a woodworking shop, a stained-glass workshop, and a food store selling bulk items. Commune members grew their own food in gardens, engaged in artistic pursuits, and gathered for holiday dinners and celebrations.
Three creeks, each with an interesting history, spring from Black Mountain and flow to southwest San Francisco Bay
.
Stevens Creek originates in the Montebello Open Space Reserve on the west flank of the mountain and flows southeast then north to the Bay. Stevens Creek was originally called Arroyo San José de Cupertino by Spanish
explorer Juan Bautista de Anza
, who camped along the creek on his expedition from Monterey to San Francisco. De Anza completed the first overland route to San Francisco Bay
when he and Father Pedro Font sighted the bay from a prominent knoll near the entry of Rancho San Antonio County Park
. In de Anza's diary on March 25, 1776 he states that he "arrived at the "Arroyo San José de Cupertino", which is useful only for travelers. Here we halted for the night, having come eight leagues in seven and a half hours. From this place we have seen at our right the estuary which runs from the port of San Francisco." The Arroyo San José de Cupertino became Cupertino Creek, but was later re-named for Elijah Stephens (how his name was misspelled is unknown), a South Carolina
-born blacksmith and trapper who settled on Cupertino Creek in 1848. Stephens renamed his 160 acre property at the base of Black Mountain "Blackberry Farm". Stephens is notable for being the captain of the Stephens-Townsend-Murphy Party
, the first wagon train to cross the Sierra Nevada (two years before the ill-fated Donner Party
).
Adobe Creek
, originally named Yeguas Creek then San Antonio Creek, flows down Black Mountain's north flank to the Bay at the Palo Alto Flood Basin, just west of the Bay Trail
on the levee separating it from Charleston Slough. The founders of Adobe Systems
, a software company, lived next to Adobe Creek in Los Altos
, and named their company after the creek. The upper watershed of Adobe Creek is protected by the Hidden Villa
, a nonprofit educational organization founded by Frank and Josephine Duveneck, who purchased the land in 1924 and offered it as a gathering place for discussion, reflection, and incubation of social reform. Over the following decades, the Duvenecks established the first Hostel on the Pacific Coast (1937), the first multiracial summer camp (1945), and Hidden Villa’s Environmental Education Program (1970).
Permanente Creek
, named Rio Permanente by early Spanish explorers because of its perennial flow, descends the east flank of Black Mountain then courses north to the Bay at the Mountain View Slough. Permanente Creek is also the namesake for Kaiser Permanente
. Bess Kaiser and her spouse, industrialist Henry Kaiser
, had a lodge on the creek's headwaters above the large Permanente Quarry and Cement Plant, and, in 1945, Bess felt that the name of their attractive and dependable stream would be a good name for their medical program at the shipyards. That medical program became Kaiser Permanente
.
From its name, Black Mountain's dark summit was once covered with forest or chaparral instead of the current grasslands. Evidence of a large historic Coast Douglas-fir
(Pseudotsuga menziesii var. menziesii) forest includes the "Skid Road Trail" in the Stevens Creek valley west of Black Mountain. Nineteenth century loggers used oxen to drag huge firs and smaller Tanbark oak (Lithocarpus densiflorus) trees along the trail. "Skids" were flat-topped logs doused with water to reduce friction. Although the summit today is mostly grassland and oak, the Stevens Creek valley contains the last remaining Douglas-fir forest in Santa Clara County. Until the 1975 conversion of Black Mountain to open space
by the Midpeninsula Regional Open Space District
, forest succession was inhibited by grazing dairy cattle. Today, saplings sown by large remnant Douglas-fir trees are distributed widely over the mountain in an example of forest succession.
The Monte Bello ridge's grasslands include California poppy, checker mallow, purple owl's-clover, bluedicks, and blue-eyed grass. Large mammals on the ridge include coyote, bobcat, deer, badger and mountain lions. Common raptors include red-tailed hawks, northern harriers, and American kestrels, and less commonly, rough-legged hawks, prairie falcons, merlins, and golden eagles can be seen during fall and spring migratory seasons. Monte Bello hosts a wide variety of owl species, including great horned, barn, pygmy, long-eared, western screech, and northern saw-whet. Secretive Virginia rail
s (Rallus limicola) inhabit the sag pond
at the beginning of the Canyon Trail.
. The San Andreas Fault
runs along the base of Monte Bello Ridge, of which Black Mountain is the highest point at 2812 feet (857.1 m). It is the second highest summit on the Sierra Morena portion of the Santa Cruz Mountains, after Castle Rock
at 3,214 feet. Everything west of the San Andreas fault rides to the northwest on the Pacific Plate's Salinian Block
, which is made up largely of Mesozoic-era granitic rocks, similar to those of the Sierra Nevada Mountains, and overlain by more recent sedimentary rocks of marine origin. East of the fault, the North American Plate
rides to the southeast, and here the bedrock is the Franciscan Assemblage
, made up of rocks common in the Bay Area such as sandstone, basalt, and metamorphics. On the very summit of Black Mountain are Calera limestone rocks which are relatively unique in the Bay Area. Microfossils in the limestone deposits suggest that the mountain originated as a seamount at 22 degrees north in the tropical Pacific about 100 million years ago and was transported to Los Altos
by the Pacific Plate
. These rocks occur as jagged gray boulders and outcrops just southwest of the radio towers on the summit, as well as in the large Permanente Quarry downhill east of the preserve where the limestone is mined to produce cement. The summit is also unusual as it is higher than the Skyline Ridge to the west, allowing a view of the ocean on a clear day.
Small quantities of gold and mercury have been mined from the mountain. Legend has it that a lone Indian eked out a living on gold extracted from a "lost mine". The location has since been lost.
by a 5 miles (8 km) route from about 400 feet (121.9 m). This strenuous hike is not recommended for novice or beginning hikers.
The summit can also be reached by Montebello Road which begins near the Stevens Creek Reservoir
. This maintained road can be followed most of the way to the summit. It has an average grade of 15% and while it is open to motor vehicles the traffic is comparatively light. On the summit there are two broadcasting stations. One is a private radio station owned by Stanford University
, and the other is owned by the Federal Aviation Administration
.
There are several wineries
along Montebello Road, including Ridge Vineyards
, Fellom Ranch Vineyards and Picchetti Brothers Winery
.
Santa Cruz Mountains
The Santa Cruz Mountains, part of the Pacific Coast Ranges, are a mountain range in central California, United States. They form a ridge along the San Francisco Peninsula, south of San Francisco, separating the Pacific Ocean from San Francisco Bay and the Santa Clara Valley, and continuing south,...
of west Santa Clara County, California
Santa Clara County, California
Santa Clara County is a county located at the southern end of the San Francisco Bay Area in the U.S. state of California. As of 2010 it had a population of 1,781,642. The county seat is San Jose. The highly urbanized Santa Clara Valley within Santa Clara County is also known as Silicon Valley...
, south of Los Altos
Los Altos, California
Los Altos is a city at the southern end of the San Francisco Peninsula, in the San Francisco Bay Area. The city is in Santa Clara County, California, United States. The population was 28,976 according to the 2010 census....
and west of Cupertino
Cupertino, California
Cupertino is an affluent suburban city in Santa Clara County, California in the U.S., directly west of San Jose on the western edge of the Santa Clara Valley with portions extending into the foothills of the Santa Cruz Mountains. The population was 58,302 at the time of the 2010 census. Forbes...
. It is located on the border between Rancho San Antonio Open Space Preserve
Rancho San Antonio Open Space Preserve
Rancho San Antonio County Park is a public recreational area in the Santa Cruz Mountains, Santa Clara County, in northern California. It's approximately in area and contains of hiking trails. It is managed by the Santa Clara County Parks department...
and Monte Bello Open Space Preserve
Monte Bello Open Space Preserve
Monte Bello Open Space Preserve is a open space preserve, located near Palo Alto in the Santa Cruz Mountains, in San Mateo and Santa Clara Counties, California. The preserve encompasses the upper Stevens Creek watershed in the valley between Monte Bello Ridge and Skyline Ridge...
, with the summit located in the former. Early Spanish explorers commonly named tree- or chaparral-covered summits which look black in the distance Loma Prieta, from the Spanish (loma-hill, prieta-dark).
The Spanish also called the middle portion of the Santa Cruz Mountains the Sierra Morena meaning (morena-brunette, sierra-mountain range), extending from Half Moon Bay Road (California State Route 92
California State Route 92
State Route 92 is an east-west highway in the San Francisco Bay area between Half Moon Bay near the coast in the west and downtown Hayward at its junction with State Route 238 and State Route 185. It is most notable for being the route that traverses the San Mateo Bridge. It has interchanges with...
) south to a gap at Lexington Reservoir
Lexington Reservoir
Lexington Reservoir is an artificial lake on the Los Gatos Creek near Los Gatos, California. The James J. Lenihan Dam, a high, thick earthen dam, forms the third-largest reservoir in Santa Clara County.-Background:...
, and which includes a summit called Sierra Morena.
There are over 100 "Black Mountains" in California.
History
After extensive logging operations in the nineteenth century, Italian farmers and winemakers settled on the flanks of Montebello Ridge. Dairies in the Santa Cruz Mountains supplied much of the milk for San FranciscoSan Francisco, California
San Francisco , officially the City and County of San Francisco, is the financial, cultural, and transportation center of the San Francisco Bay Area, a region of 7.15 million people which includes San Jose and Oakland...
and the Peninsula
San Francisco Peninsula
The San Francisco Peninsula is a peninsula in the San Francisco Bay Area that separates the San Francisco Bay from the Pacific Ocean. On its northern tip is the City and County of San Francisco. Its southern base is in Santa Clara County, including the cities of Palo Alto, Los Altos, and Mountain...
. There was a large dairy near what is now the Montebello Open Space Preserve's main parking area on Page Mill Road, and cattle freely grazed the slopes of Black Mountain. Ranch buildings dotted the landscape.
Oseo Perrone, a physician and immigrant from Mattarana, La Spezia Province, Italy, came to San Francisco in 1881, became interested in viticulture and purchased a large ranch at 2600 feet (792.5 m) on Black Mountain in 1885 where he, and then his nephew of the same name, began production of Montebello Winery (now Ridge Vineyards
Ridge Vineyards
Ridge Vineyards is a California winery specializing in premium Cabernet Sauvignon, Zinfandel, and Chardonnay wines. Ridge produces wine at two winery locations in northern California...
) wine in 1892.
George Morell, founding publisher of the Palo Alto Times and a Trustee of Stanford University
Stanford University
The Leland Stanford Junior University, commonly referred to as Stanford University or Stanford, is a private research university on an campus located near Palo Alto, California. It is situated in the northwestern Santa Clara Valley on the San Francisco Peninsula, approximately northwest of San...
, bought the Black Mountain Ranch on the mountain's summit in 1940. “Nature in the raw” is what led Mr. Morell to buy Black Mountain Ranch, according to his essay, “History of Black Mountain and Monte Bello Ridge,” written in 1959. Morell donated the land comprising the former Johnson, Winship, Morell ranches to Stanford University
Stanford University
The Leland Stanford Junior University, commonly referred to as Stanford University or Stanford, is a private research university on an campus located near Palo Alto, California. It is situated in the northwestern Santa Clara Valley on the San Francisco Peninsula, approximately northwest of San...
.
In 1975, when the Black Mountain Ranch lands were acquired by the Midpeninsula Regional Open Space District
Midpeninsula Regional Open Space District
The Midpeninsula Regional Open Space District is a special-purpose district that manages over of open space in 25 preserves in the San Francisco Bay Area. It includes parts of Santa Clara, San Mateo and Santa Cruz Counties. The District was created by voter initiative in 1972...
(MROSD) from Stanford, a commune of about 100 people, called "The Land", were evicted. The Land lived along the Canyon Trail from Page Mill Road to Indian Creek and built a variety of dwellings on platforms scattered amongst the oak woodlands and secluded canyons. A large ranch building was used as a central dining hall, and maintained a woodworking shop, a stained-glass workshop, and a food store selling bulk items. Commune members grew their own food in gardens, engaged in artistic pursuits, and gathered for holiday dinners and celebrations.
Three creeks, each with an interesting history, spring from Black Mountain and flow to southwest San Francisco Bay
San Francisco Bay
San Francisco Bay is a shallow, productive estuary through which water draining from approximately forty percent of California, flowing in the Sacramento and San Joaquin rivers from the Sierra Nevada mountains, enters the Pacific Ocean...
.
Stevens Creek originates in the Montebello Open Space Reserve on the west flank of the mountain and flows southeast then north to the Bay. Stevens Creek was originally called Arroyo San José de Cupertino by Spanish
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
explorer Juan Bautista de Anza
Juan Bautista de Anza
Juan Bautista de Anza Bezerra Nieto was a Novo-Spanish explorer and Governor of New Mexico for the Spanish Empire.-Early life:...
, who camped along the creek on his expedition from Monterey to San Francisco. De Anza completed the first overland route to San Francisco Bay
San Francisco Bay
San Francisco Bay is a shallow, productive estuary through which water draining from approximately forty percent of California, flowing in the Sacramento and San Joaquin rivers from the Sierra Nevada mountains, enters the Pacific Ocean...
when he and Father Pedro Font sighted the bay from a prominent knoll near the entry of Rancho San Antonio County Park
Rancho San Antonio Open Space Preserve
Rancho San Antonio County Park is a public recreational area in the Santa Cruz Mountains, Santa Clara County, in northern California. It's approximately in area and contains of hiking trails. It is managed by the Santa Clara County Parks department...
. In de Anza's diary on March 25, 1776 he states that he "arrived at the "Arroyo San José de Cupertino", which is useful only for travelers. Here we halted for the night, having come eight leagues in seven and a half hours. From this place we have seen at our right the estuary which runs from the port of San Francisco." The Arroyo San José de Cupertino became Cupertino Creek, but was later re-named for Elijah Stephens (how his name was misspelled is unknown), a South Carolina
South Carolina
South Carolina is a state in the Deep South of the United States that borders Georgia to the south, North Carolina to the north, and the Atlantic Ocean to the east. Originally part of the Province of Carolina, the Province of South Carolina was one of the 13 colonies that declared independence...
-born blacksmith and trapper who settled on Cupertino Creek in 1848. Stephens renamed his 160 acre property at the base of Black Mountain "Blackberry Farm". Stephens is notable for being the captain of the Stephens-Townsend-Murphy Party
Stephens-Townsend-Murphy Party
The Stephens-Townsend-Murphy Party consisted of ten families who migrated from Iowa to California prior to the Mexican-American War or the California Gold Rush. The Stephens Party is significant in California history because they were the first wagon train to cross the Sierra Nevada during the...
, the first wagon train to cross the Sierra Nevada (two years before the ill-fated Donner Party
Donner Party
The Donner Party was a group of American pioneers who set out for California in a wagon train. Delayed by a series of mishaps, they spent the winter of 1846–47 snowbound in the Sierra Nevada...
).
Adobe Creek
Adobe Creek (near Los Altos)
Adobe Creek is a northward-flowing stream originating on Black Mountain in Santa Clara County, California, United States. It courses through the cities of Los Altos Hills, Los Altos, and Palo Alto, culminating in southwest San Francisco Bay just west of the levee separating the Palo Alto Flood...
, originally named Yeguas Creek then San Antonio Creek, flows down Black Mountain's north flank to the Bay at the Palo Alto Flood Basin, just west of the Bay Trail
San Francisco Bay Trail
The San Francisco Bay Trail is a bicycle and pedestrian trail that will eventually allow continuous travel around the shoreline of San Francisco Bay. As of 2011, approximately 310 miles of trail have been completed...
on the levee separating it from Charleston Slough. The founders of Adobe Systems
Adobe Systems
Adobe Systems Incorporated is an American computer software company founded in 1982 and headquartered in San Jose, California, United States...
, a software company, lived next to Adobe Creek in Los Altos
Los Altos
Los Altos is the name of several places, including:* the former state of Los Altos, Central America, now divided between Guatemala and Mexico.* the city of Los Altos, California, in the United States....
, and named their company after the creek. The upper watershed of Adobe Creek is protected by the Hidden Villa
Hidden Villa
Hidden Villa is a United States nonprofit educational organization teaching programs on environmental and multicultural awareness. In 1924, Frank and Josephine Duveneck founded this working organic farm and wilderness area on land comprising the upper Adobe Creek watershed on the foothills of Black...
, a nonprofit educational organization founded by Frank and Josephine Duveneck, who purchased the land in 1924 and offered it as a gathering place for discussion, reflection, and incubation of social reform. Over the following decades, the Duvenecks established the first Hostel on the Pacific Coast (1937), the first multiracial summer camp (1945), and Hidden Villa’s Environmental Education Program (1970).
Permanente Creek
Permanente Creek
Permanente Creek is a stream originating on Black Mountain in Santa Clara County, California, United States. It is the namesake for the Kaiser Permanente health maintenance organization...
, named Rio Permanente by early Spanish explorers because of its perennial flow, descends the east flank of Black Mountain then courses north to the Bay at the Mountain View Slough. Permanente Creek is also the namesake for Kaiser Permanente
Kaiser Permanente
Kaiser Permanente is an integrated managed care consortium, based in Oakland, California, United States, founded in 1945 by industrialist Henry J. Kaiser and physician Sidney Garfield...
. Bess Kaiser and her spouse, industrialist Henry Kaiser
Henry Kaiser
Henry Kaiser may refer to:People*Henry Felix Kaiser , American academic known for the varimax rotation*Henry J. Kaiser , American industrialist and shipbuilder who founded Kaiser Permanente...
, had a lodge on the creek's headwaters above the large Permanente Quarry and Cement Plant, and, in 1945, Bess felt that the name of their attractive and dependable stream would be a good name for their medical program at the shipyards. That medical program became Kaiser Permanente
Kaiser Permanente
Kaiser Permanente is an integrated managed care consortium, based in Oakland, California, United States, founded in 1945 by industrialist Henry J. Kaiser and physician Sidney Garfield...
.
Habitat and wildlife
Rainfall on the summit of Black Mountain averages 40 inches (1 m) per year, much higher than the Santa Clara Valley which lies in its rain shadow.From its name, Black Mountain's dark summit was once covered with forest or chaparral instead of the current grasslands. Evidence of a large historic Coast Douglas-fir
Coast Douglas-fir
Pseudotsuga menziesii, known as Douglas-fir, Oregon Pine, or Douglas spruce, is an evergreen conifer species native to western North America. Its variety Pseudotsuga menziesii var. menziesii, also known as coast Douglas-fir grows in the coastal regions, from west-central British Columbia, Canada...
(Pseudotsuga menziesii var. menziesii) forest includes the "Skid Road Trail" in the Stevens Creek valley west of Black Mountain. Nineteenth century loggers used oxen to drag huge firs and smaller Tanbark oak (Lithocarpus densiflorus) trees along the trail. "Skids" were flat-topped logs doused with water to reduce friction. Although the summit today is mostly grassland and oak, the Stevens Creek valley contains the last remaining Douglas-fir forest in Santa Clara County. Until the 1975 conversion of Black Mountain to open space
Open space reserve
Open space reserve, open space preserve, and open space reservation, are planning and conservation ethics terms used to describe areas of protected or conserved land or water on which development is indefinitely set aside...
by the Midpeninsula Regional Open Space District
Midpeninsula Regional Open Space District
The Midpeninsula Regional Open Space District is a special-purpose district that manages over of open space in 25 preserves in the San Francisco Bay Area. It includes parts of Santa Clara, San Mateo and Santa Cruz Counties. The District was created by voter initiative in 1972...
, forest succession was inhibited by grazing dairy cattle. Today, saplings sown by large remnant Douglas-fir trees are distributed widely over the mountain in an example of forest succession.
The Monte Bello ridge's grasslands include California poppy, checker mallow, purple owl's-clover, bluedicks, and blue-eyed grass. Large mammals on the ridge include coyote, bobcat, deer, badger and mountain lions. Common raptors include red-tailed hawks, northern harriers, and American kestrels, and less commonly, rough-legged hawks, prairie falcons, merlins, and golden eagles can be seen during fall and spring migratory seasons. Monte Bello hosts a wide variety of owl species, including great horned, barn, pygmy, long-eared, western screech, and northern saw-whet. Secretive Virginia rail
Virginia Rail
The Virginia Rail, Rallus limicola, is a small waterbird, of the family Rallidae.Adults are mainly brown, darker on the back and crown, with orange-brown legs. They have long toes, a short tail and a long slim reddish bill...
s (Rallus limicola) inhabit the sag pond
Sag pond
A sag pond is a body of water, which forms as water collects in the lowest parts of the depression that forms between two strands of an active strike-slip fault. The relative motion of the two fault strands results in a stretching of the land between them, causing the land between them to...
at the beginning of the Canyon Trail.
Geology
The geology of the mountain is complex and has features different from the rest of the Santa Cruz MountainsSanta Cruz Mountains
The Santa Cruz Mountains, part of the Pacific Coast Ranges, are a mountain range in central California, United States. They form a ridge along the San Francisco Peninsula, south of San Francisco, separating the Pacific Ocean from San Francisco Bay and the Santa Clara Valley, and continuing south,...
. The San Andreas Fault
San Andreas Fault
The San Andreas Fault is a continental strike-slip fault that runs a length of roughly through California in the United States. The fault's motion is right-lateral strike-slip...
runs along the base of Monte Bello Ridge, of which Black Mountain is the highest point at 2812 feet (857.1 m). It is the second highest summit on the Sierra Morena portion of the Santa Cruz Mountains, after Castle Rock
Castle Rock State Park (California)
Castle Rock State Park is a state park of California, USA, located along the crest of the Santa Cruz Mountains. It embraces coast redwood, Douglas fir, and madrone forest, most of which has been left in its wild, natural state. Steep canyons are sprinkled with unusual rock formations that is a...
at 3,214 feet. Everything west of the San Andreas fault rides to the northwest on the Pacific Plate's Salinian Block
Salinian Block
The Salinian Block or Salinian terrane is a geologic terrane which lies west of the main trace of the San Andreas Fault system in California. It is bounded on the south by the Big Pine Fault in Ventura County, and on the west by the Nacimiento Fault...
, which is made up largely of Mesozoic-era granitic rocks, similar to those of the Sierra Nevada Mountains, and overlain by more recent sedimentary rocks of marine origin. East of the fault, the North American Plate
North American Plate
The North American Plate is a tectonic plate covering most of North America, Greenland, Cuba, Bahamas, and parts of Siberia, Japan and Iceland. It extends eastward to the Mid-Atlantic Ridge and westward to the Chersky Range in eastern Siberia. The plate includes both continental and oceanic crust...
rides to the southeast, and here the bedrock is the Franciscan Assemblage
Franciscan Assemblage
The Franciscan Assemblage is a geological term for an accreted terrane of heterogeneous rocks found on and near the San Francisco Peninsula. It was named by geologist Andrew Lawson who also named the San Andreas Fault which bounds the Franciscan Assemblage....
, made up of rocks common in the Bay Area such as sandstone, basalt, and metamorphics. On the very summit of Black Mountain are Calera limestone rocks which are relatively unique in the Bay Area. Microfossils in the limestone deposits suggest that the mountain originated as a seamount at 22 degrees north in the tropical Pacific about 100 million years ago and was transported to Los Altos
Los Altos, California
Los Altos is a city at the southern end of the San Francisco Peninsula, in the San Francisco Bay Area. The city is in Santa Clara County, California, United States. The population was 28,976 according to the 2010 census....
by the Pacific Plate
Pacific Plate
The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At 103 million square kilometres, it is the largest tectonic plate....
. These rocks occur as jagged gray boulders and outcrops just southwest of the radio towers on the summit, as well as in the large Permanente Quarry downhill east of the preserve where the limestone is mined to produce cement. The summit is also unusual as it is higher than the Skyline Ridge to the west, allowing a view of the ocean on a clear day.
Small quantities of gold and mercury have been mined from the mountain. Legend has it that a lone Indian eked out a living on gold extracted from a "lost mine". The location has since been lost.
Black Mountain today
The mountain is a popular destination for hikers and mountain bikers. The summit is most easily accessed from the Monte Bello parking area on Page Mill Road, via a 2.5 miles (4 km) route from about 2200 feet (670.6 m). The summit can also be reached from the northwestern entrance of Rancho San Antonio on Rhus Ridge Road in Los Altos HillsLos Altos Hills, California
Los Altos Hills is an incorporated town in Santa Clara County, California, United States. The population was 7,922 at the 2010 census. Located in Silicon Valley, Los Altos Hills is one of the wealthiest cities in the nation.-Strictly residential:...
by a 5 miles (8 km) route from about 400 feet (121.9 m). This strenuous hike is not recommended for novice or beginning hikers.
The summit can also be reached by Montebello Road which begins near the Stevens Creek Reservoir
Stevens Creek Reservoir
Stevens Creek Reservoir is a reservoir located in the foothills of the Santa Cruz Mountains near Cupertino, California.Stevens Creek Dam, which impounds the lake, was approved for construction by voters in 1934 and completed in 1935. The dam's height was raised 10 feet in 1985, to its present...
. This maintained road can be followed most of the way to the summit. It has an average grade of 15% and while it is open to motor vehicles the traffic is comparatively light. On the summit there are two broadcasting stations. One is a private radio station owned by Stanford University
Stanford University
The Leland Stanford Junior University, commonly referred to as Stanford University or Stanford, is a private research university on an campus located near Palo Alto, California. It is situated in the northwestern Santa Clara Valley on the San Francisco Peninsula, approximately northwest of San...
, and the other is owned by the Federal Aviation Administration
Federal Aviation Administration
The Federal Aviation Administration is the national aviation authority of the United States. An agency of the United States Department of Transportation, it has authority to regulate and oversee all aspects of civil aviation in the U.S...
.
There are several wineries
Winery
A winery is a building or property that produces wine, or a business involved in the production of wine, such as a wine company. Some wine companies own many wineries. Besides wine making equipment, larger wineries may also feature warehouses, bottling lines, laboratories, and large expanses of...
along Montebello Road, including Ridge Vineyards
Ridge Vineyards
Ridge Vineyards is a California winery specializing in premium Cabernet Sauvignon, Zinfandel, and Chardonnay wines. Ridge produces wine at two winery locations in northern California...
, Fellom Ranch Vineyards and Picchetti Brothers Winery
Picchetti Brothers Winery
The Picchetti Brothers Winery, also known as the Picchetti Ranch, is a winery located at 13100 Montebello Rd., Cupertino, California in the Picchetti Ranch Open Space Preserve...
.
See also
- Adobe Creek (near Los Altos, California)
- Permanente CreekPermanente CreekPermanente Creek is a stream originating on Black Mountain in Santa Clara County, California, United States. It is the namesake for the Kaiser Permanente health maintenance organization...
- Stevens Creek (California)