Berkeley Hills
Encyclopedia
The Berkeley Hills are a range of the Pacific Coast Ranges
that overlook the northeast side of the valley
that surrounds San Francisco Bay
. They were previously called the "Contra Costa Range/Hills" (from the original Spanish Sierra de la Contra Costa), but with the establishment of Berkeley
and the University of California
, the current usage was applied by geographers and gazetteers.
on their eastern side. The highest peaks are Vollmer Peak (elevation 1,905 feet/581m), Grizzly Peak
(elevation 1,754 feet/535 m) and Round Top
(elevation 1,761 feet/537m), an extinct volcano, and William Rust Summit 1,004 feet.
Vollmer Peak was named for the first police chief of the City of Berkeley, August Vollmer
. It was formerly known as "Bald Peak".
The eastern slope of the Berkeley Hills, by contrast, is mostly preserved or partially developed wildland, a good portion of which is owned by the East Bay Regional Park District
and the East Bay Municipal Utility District
(EBMUD).
The Berkeley Hills are pierced by several tunnels. Two of these are aqueducts of EBMUD. The Berkeley Hills Tunnel
serves the Pittsburg-Baypoint line of the Bay Area Rapid Transit
(BART) system. The three bores (soon to be four) of the Caldecott Tunnel
carry State Highway 24 between Oakland and Contra Costa County.
" to refer to that section of the Berkeley Hills that runs along the east side of Oakland
, but as a proper name or officially-recognized toponym, it is technically incorrect. However, the exact southern terminus of the usage "Berkeley Hills" is unclear. It does not, in any case, correspond to any political boundaries, only to a geographic feature (much as "San Francisco Bay" is not limited to that stretch of the Pacific inlet within the bounds of the City and County of San Francisco). The same ridge does in fact extend south through Oakland and San Leandro to the drainage of San Leandro Creek
called Castro Valley, and geologically, continues southward above the line of the Hayward Fault. In the section above East Oakland to Castro Valley, the ridge appears on most maps as the "San Leandro Hills".
The northern extent of the proper name "Berkeley Hills" is less indefinite; most maps including those of the USGS apply the name along the entire ridge as it runs continuously right up to the shoreline of San Pablo Bay
north of Richmond
. The eastern slopes of the Berkeley Hills lie entirely outside of the city of Berkeley within Contra Costa County.
Another common informal usage is East Bay Hills, but its application to any particular range east of San Francisco Bay is very unclear. In some contexts, it may refer collectively to all of the ranges east of the Bay, from the Berkeley Hills to the Diablo Range
and all the ranges between.
, which is most developed during the summer months, is usually less than 2,000 feet deep and thus is blocked by the range. This produces a "fog shadow" effect on the areas directly east, which are consequently warmer than areas west of the hills. The westerly wind that carries the marine layer through the Golden Gate typically splits its flow as it hits the Berkeley Hills producing a southerly wind from Berkeley northward and a northerly flow in the direction of Oakland. In winter during spells of tule fog
inland, the reverse occurs, with the fog usually confined to areas east of the hills.
The Berkeley Hills also have an effect on rainfall. When the wind direction is oriented perpendicular to the hills (southwest wind) during a rain event, air is forced to rise, cooling and condensing additional moisture, increasing the amount of precipitation along the western slopes, and leaving areas east of the hills relatively drier.
In winter, an especially cold storm will deposit wet snow on the peaks. A particularly favored spot is along Grizzly Peak Boulevard in the vicinity of the Miniature Train Ride and Grizzly Stables (Lomas Cantadas Road).
In the spring and fall, strongly sinking air from aloft combining with inland high pressure periodically sends hot, dry, and gusty wind
s across the ridges of the Berkeley Hills, posing a significant fire danger, which in the 20th century produced several wildfires, two of which caused major damage to Berkeley and Oakland. (See 1923 Berkeley Fire
and 1991 Oakland firestorm
).
Pacific Coast Ranges
The Pacific Coast Ranges and the Pacific Mountain System are the series of mountain ranges that stretch along the West Coast of North America from Alaska south to Northern and Central Mexico...
that overlook the northeast side of the valley
Valley
In geology, a valley or dale is a depression with predominant extent in one direction. A very deep river valley may be called a canyon or gorge.The terms U-shaped and V-shaped are descriptive terms of geography to characterize the form of valleys...
that surrounds 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...
. They were previously called the "Contra Costa Range/Hills" (from the original Spanish Sierra de la Contra Costa), but with the establishment of Berkeley
Berkeley, California
Berkeley is a city on the east shore of the San Francisco Bay in Northern California, United States. Its neighbors to the south are the cities of Oakland and Emeryville. To the north is the city of Albany and the unincorporated community of Kensington...
and the University of California
University of California
The University of California is a public university system in the U.S. state of California. Under the California Master Plan for Higher Education, the University of California is a part of the state's three-tier public higher education system, which also includes the California State University...
, the current usage was applied by geographers and gazetteers.
Geology
Tectonically, the Berkeley Hills are bounded by the major Hayward Fault along their western base, and the minor Wildcat FaultWildcat Canyon
Wildcat Canyon is a narrow linear valley just east of the Berkeley Hills in the San Francisco Bay Area, situated in Contra Costa County, California. The canyon is bounded on its east side by the San Pablo Ridge, and is drained by Wildcat Creek which runs northwest to its outlet in San Pablo Bay. ...
on their eastern side. The highest peaks are Vollmer Peak (elevation 1,905 feet/581m), Grizzly Peak
Grizzly Peak (Berkeley Hills)
Grizzly Peak is a summit in the Berkeley Hills above Berkeley, California. The peak is located on the border between Alameda and Contra Costa counties, within the boundaries of Tilden Regional Park, and directly behind the University of California, Berkeley campus.The peak was named for the...
(elevation 1,754 feet/535 m) and Round Top
Round Top
Round Top is an extinct volcano in the Berkeley Hills, just east of Oakland, California. The peak lies entirely within the bounds of Contra Costa County. In 1936, the area surrounding the peak was established as Round Top Regional Park, one of the first three parks of the East Bay Regional Parks...
(elevation 1,761 feet/537m), an extinct volcano, and William Rust Summit 1,004 feet.
Vollmer Peak was named for the first police chief of the City of Berkeley, August Vollmer
August Vollmer
August "Gus" Vollmer was a leading figure in the development of the field of criminal justice in the United States in the early 20th century. He was also the first police chief of Berkeley, California.-Youth:...
. It was formerly known as "Bald Peak".
Development
Much of the western slope of the Berkeley Hills is occupied by densely-built residential neighborhoods of mostly single family homes, except on the land of the University of California. Most of the streets are narrow and many tend to follow the contours of the land, although there are at least three streets, Marin Avenue, Moeser Lane, and Potrero Avenue, which go directly up toward the ridgeline. Other roads to the ridgeline wind their way up the various canyons. Near the ridgeline and generally following its contour are Grizzly Peak and Skyline Blvds.The eastern slope of the Berkeley Hills, by contrast, is mostly preserved or partially developed wildland, a good portion of which is owned by the East Bay Regional Park District
East Bay Regional Park District
The East Bay Regional Park District is a special district operating in Alameda County and Contra Costa County, California, within the East Bay area of the San Francisco Bay Area...
and the East Bay Municipal Utility District
East Bay Municipal Utility District
East Bay Municipal Utility District , colloquially referred to as "East Bay Mud", provides water and sewage treatment for customers in portions of Alameda County and Contra Costa County in California, on the eastern side of San Francisco Bay, including the cities of Richmond, El Cerrito, Hercules,...
(EBMUD).
The Berkeley Hills are pierced by several tunnels. Two of these are aqueducts of EBMUD. The Berkeley Hills Tunnel
Berkeley Hills Tunnel
The Berkeley Hills Tunnel is a tunnel carrying the Pittsburg/Bay Point - SFO Line of the Bay Area Rapid Transit system beneath Grizzly Peak between the Rockridge and Orinda stations...
serves the Pittsburg-Baypoint line of the Bay Area Rapid Transit
Bay Area Rapid Transit
Bay Area Rapid Transit is a rapid transit system serving the San Francisco Bay Area. The heavy-rail public transit and subway system connects San Francisco with cities in the East Bay and suburbs in northern San Mateo County. BART operates five lines on of track with 44 stations in four counties...
(BART) system. The three bores (soon to be four) of the Caldecott Tunnel
Caldecott Tunnel
The Caldecott Tunnel is a three bore highway tunnel between Oakland, California and Contra Costa County, California. The east-west tunnel is signed as a part of State Route 24, which is also known as the William Byron Rumford...
carry State Highway 24 between Oakland and Contra Costa County.
Usage
It is common in recent years to hear the term, "Oakland HillsOakland Hills, Oakland, California
Oakland Hills is an informal term used to indicate the city neighborhoods lying within the eastern portion of Oakland, California.-The geologic feature:...
" to refer to that section of the Berkeley Hills that runs along the east side of Oakland
Oakland, California
Oakland is a major West Coast port city on San Francisco Bay in the U.S. state of California. It is the eighth-largest city in the state with a 2010 population of 390,724...
, but as a proper name or officially-recognized toponym, it is technically incorrect. However, the exact southern terminus of the usage "Berkeley Hills" is unclear. It does not, in any case, correspond to any political boundaries, only to a geographic feature (much as "San Francisco Bay" is not limited to that stretch of the Pacific inlet within the bounds of the City and County of San Francisco). The same ridge does in fact extend south through Oakland and San Leandro to the drainage of San Leandro Creek
San Leandro Creek
San Leandro Creek is a year-round natural stream flowing along the east side of the range which comprises the Berkeley Hills and the San Leandro Hills, immediately east of Oakland. In the hills, it runs into Upper San Leandro Reservoir and then Lake Chabot, both manmade lakes lying north of the...
called Castro Valley, and geologically, continues southward above the line of the Hayward Fault. In the section above East Oakland to Castro Valley, the ridge appears on most maps as the "San Leandro Hills".
The northern extent of the proper name "Berkeley Hills" is less indefinite; most maps including those of the USGS apply the name along the entire ridge as it runs continuously right up to the shoreline of San Pablo Bay
San Pablo Bay
San Pablo Bay is a tidal estuary that forms the northern extension of San Francisco Bay in northern California in the United States. Most of the Bay is shallow; however, there is a deep water channel approximately in mid bay, which allows access to Sacramento, Stockton, Benicia, Martinez, and...
north of Richmond
Richmond, California
Richmond is a city in western Contra Costa County, California, United States. The city was incorporated on August 7, 1905. It is located in the East Bay, part of the San Francisco Bay Area. It is a residential inner suburb of San Francisco, as well as the site of heavy industry, which has been...
. The eastern slopes of the Berkeley Hills lie entirely outside of the city of Berkeley within Contra Costa County.
Another common informal usage is East Bay Hills, but its application to any particular range east of San Francisco Bay is very unclear. In some contexts, it may refer collectively to all of the ranges east of the Bay, from the Berkeley Hills to the Diablo Range
Diablo Range
The Diablo Range is a mountain range in the California Coast Ranges subdivision of the Pacific Coast Ranges. It is located in the eastern San Francisco Bay area south to the Salinas Valley area of northern California, the United States.-Geography:...
and all the ranges between.
Climatic effects
The Berkeley Hills affect the local climate by their elevation and situation. The oceanic marine layerMarine layer
A marine layer is an air mass which develops over the surface of a large body of water such as the ocean or large lake in the presence of a temperature inversion. The inversion itself is usually initiated by the cooling effect of the water on the surface layer of an otherwise warm air mass...
, which is most developed during the summer months, is usually less than 2,000 feet deep and thus is blocked by the range. This produces a "fog shadow" effect on the areas directly east, which are consequently warmer than areas west of the hills. The westerly wind that carries the marine layer through the Golden Gate typically splits its flow as it hits the Berkeley Hills producing a southerly wind from Berkeley northward and a northerly flow in the direction of Oakland. In winter during spells of tule fog
Tule fog
Tule fog is a thick ground fog that settles in the San Joaquin Valley and Sacramento Valley areas of California's Great Central Valley. Tule fog forms during the late fall and winter after the first significant rainfall. The official time frame for tule fog to form is from November 1 to March 31...
inland, the reverse occurs, with the fog usually confined to areas east of the hills.
The Berkeley Hills also have an effect on rainfall. When the wind direction is oriented perpendicular to the hills (southwest wind) during a rain event, air is forced to rise, cooling and condensing additional moisture, increasing the amount of precipitation along the western slopes, and leaving areas east of the hills relatively drier.
In winter, an especially cold storm will deposit wet snow on the peaks. A particularly favored spot is along Grizzly Peak Boulevard in the vicinity of the Miniature Train Ride and Grizzly Stables (Lomas Cantadas Road).
In the spring and fall, strongly sinking air from aloft combining with inland high pressure periodically sends hot, dry, and gusty wind
Diablo wind
Diablo wind is a name that has been occasionally used for the hot, dry offshore wind from the northeast that typically occurs in the San Francisco Bay Area of Northern California during the spring and fall. The same wind pattern also affects other parts of California's coastal ranges...
s across the ridges of the Berkeley Hills, posing a significant fire danger, which in the 20th century produced several wildfires, two of which caused major damage to Berkeley and Oakland. (See 1923 Berkeley Fire
1923 Berkeley Fire
The 1923 Berkeley Fire was a conflagration which consumed some 640 structures, including 584 homes in the densely-built neighborhoods north of the campus of the University of California in Berkeley, California on September 17, 1923....
and 1991 Oakland firestorm
1991 Oakland firestorm
The Oakland Firestorm of 1991 was a large urban fire that occurred on the hillsides of northern Oakland, California, and southeastern Berkeley on Sunday October 20, 1991, two years after the Loma Prieta earthquake...
).