Berkeley Hills

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Berkeley Hills
Grizzly Bench.jpg
Highest point
Elevation 581 m (1,906 ft)
Geography
Relief map of California.png
Red triangle with thick white border.svg
Location of Berkeley Hills in California [1]
CountryUnited States
StateCalifornia
District Alameda County
Range coordinates 37°52′58.732″N122°14′18.886″W / 37.88298111°N 122.23857944°W / 37.88298111; -122.23857944 Coordinates: 37°52′58.732″N122°14′18.886″W / 37.88298111°N 122.23857944°W / 37.88298111; -122.23857944
Topo map USGS  Briones Valley

The Berkeley Hills are a range of the Pacific Coast Ranges that overlook the northeast side of the valley that encompasses San Francisco Bay. They were previously called the "Contra Costa Range/Hills" [2] (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.

Contents

Geology

The Berkeley Hills are bounded by the major Hayward Fault along their western base, and the minor Wildcat fault on their eastern side. The highest peaks are Grizzly Peak (elevation 1,754 feet/535 m) and Round Top (elevation 1,761 feet/537 m), an extinct volcano, and William Rust Summit 1,004 feet (306 m).

Vollmer Peak (elevation 1,905 feet/581 m), although commonly thought to be part of the Berkeley Hills, is actually located on the adjacent San Pablo Ridge near the point where it meets the Berkeley Hills at the head of Wildcat Canyon. Vollmer Peak was named in honor of the first police chief of the City of Berkeley, August Vollmer. It was formerly known as "Bald Peak".

Development

Much of the west slope of the Berkeley Hills has residential neighborhoods of mostly single family homes, except on the land of University of California, Berkeley. Most streets are narrow and tend to follow the contours of the land, although three streets, Marin Avenue, Moeser Lane, and Potrero Avenue, run directly toward the ridgeline. Other roads to the ridgeline wind their way up the canyons. Grizzly Peak and Skyline Boulevards follow the top of the ridge. Many neighborhoods in the south Berkeley hills are home to the more affluent residents of Berkeley and Oakland.

The east slope of the Berkeley Hills is mostly preserved or partially developed wildland, much of it owned by the East Bay Regional Park District and the East Bay Municipal Utility District (EBMUD). From north to south, the parks are Wildcat Canyon Regional Park, Tilden Regional Park (includes Vollmer and Grizzly Peaks), Sibley Volcanic Regional Park (includes Round Top), Huckleberry Botanic Regional Preserve, Redwood Regional Park (enfolding Roberts Regional Recreation Area), Anthony Chabot Regional Park, Lake Chabot Regional Park, and Cull Canyon Regional Recreation Area. Claremont Canyon Regional Preserve, and Temescal Regional Park are lower on the western slopes while Las Trampas Regional Wilderness is lower on the eastern slope above Danville.

The Berkeley Hills are pierced by several tunnels. Two are aqueducts of EBMUD; the Berkeley Hills Tunnel serves the Antioch–​SFO + Millbrae Line of the Bay Area Rapid Transit (BART) system. The four bores of the Caldecott Tunnel carry State Highway 24 between Oakland and Contra Costa County.

The Berkeley Hills as seen from CA 24 near Orinda. Berkeley Hills Orinda.jpg
The Berkeley Hills as seen from CA 24 near Orinda.
Oakland and the Bay from Grizzly Peak Blvd. Dusk in the Oakland Hills - Flickr - Joe Parks.jpg
Oakland and the Bay from Grizzly Peak Blvd.

Usage

It is common to hear the term, "Oakland Hills" to refer to that section of the Berkeley Hills that runs along the east side of Oakland. As a proper name or recognized toponym, it is technically incorrect. When used on maps, the exact south end of the "Berkeley Hills" is unclear, but the maps of the USGS show them stretching well south into the northeastern portion of Oakland. [3] 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 ridge extends 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. [4]

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 mouth of Wildcat Canyon in Richmond. [5] The eastern slopes of the Berkeley Hills lie entirely outside of the city of Berkeley within Contra Costa County.

Another common usage is East Bay Hills, but its application to any particular range is unclear. It may refer to all of the ranges east of the Bay, from the Berkeley Hills to the Diablo Range and all the ranges between.

Ecology

The Berkeley Hills are a region of great biological diversity as part of Pacific Coastal Region of California and the San Francisco Bay ecosystem. Much of the area is covered by grassland which favors the southwest facing slopes. Amongst the north east hills, Baccharis Brushland and Oak Woodland are most prominent with Coast live oak and California bay laurel as some of the most prolific trees. Past Eucalyptus tree farming during the early 20th century has also introduced large Eucalyptus groves scattered across the Berkeley Hills. [6]

The area welcomes a wide variety of birds, lack-tailed deer, coyote, ground squirrel, striped skunk, western terrestrial garter snake, gray fox, bobcat, and red-tailed hawk. There are also periodic sightings of mountain lions amongst the Oak Woodland. Four protected species also call the Berkeley Hills their home, the San Francisco tree lupine moth, Alameda whipsnake, Callippe silverspot, and Bay checkerspot. Additionally, the grassland acts as an annual foraging spot for the northern harrier, American kestrel, prairie falcon, and turkey vulture.

Climatic effects

The Berkeley Hills affect the local climate by their elevation. The oceanic marine layer, which develops during the summer, bringing fog and low clouds with it, is usually less than 2,000 feet deep and thus is blocked by the range. This produces a "fog shadow" effect to the east, which is 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 wind in the direction of Oakland.

In winter during spells of tule fog inland, a reverse situation occurs, with the fog usually confined to areas east of the hills, although occasionally, the inland fog pours in from the north, around the hills by way of the Carquinez Strait.

The Berkeley Hills affect rainfall; when the wind is perpendicular to the hills (southwest wind) during a storm, air is forced to rise, cooling and condensing additional moisture, increasing the precipitation on the western slopes and leaving areas east of the hills drier. Especially cold storms occasionally deposit wet snow on the peaks.

In spring and fall, sinking air from aloft combining with inland high pressure periodically sends the Diablo Winds, a group of hot, dry, and gusty winds across the ridges of the Berkeley Hills, posing a 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).

Related Research Articles

Tilden Regional Park

Tilden Regional Park, also known as Tilden Park or Tilden, is a 2,079-acre (841 ha) regional park in the East Bay, part of the San Francisco Bay Area in California. It is between the Berkeley Hills and San Pablo Ridge. Its main entrance is near Kensington, Berkeley, and Richmond. The park is contiguous with Wildcat Canyon Regional Park.

East Bay Regional Park District

The East Bay Regional Park District (EBRPD) is a special district operating in Alameda County and Contra Costa County, California, within the East Bay area of the San Francisco Bay Area. It maintains and operates a system of regional parks which is the largest urban regional park district in the United States. The administrative office is located in Oakland.

Canyon, California Unincorporated community in California, United States

Canyon, formerly known as Sequoya, is an unincorporated community located near the border of Contra Costa and Alameda counties, in the U.S. state of California. It is situated between Oakland and Moraga in the San Francisco Bay Area. The community is named for its location in the upper canyon of San Leandro Creek along the eastern slope of the Berkeley Hills. Canyon lies at an elevation of 1138 feet.

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.

Kennedy Grove Regional Recreation Area,(KGRRA), also known simply as Kennedy Grove, is located in West Contra Costa County, California at the base of San Pablo Dam. The nearest city is El Sobrante, California. Created in 1967, it contains a three-mile hiking trail with an elevation of 760 feet (230 m). The Grove features many large eucalyptus trees, picnic areas, volleyball nets, playgrounds, and horseshoe pits. Bird watching is popular here because hawks are almost always spotted. Some hikers have reported seeing golden and bald eagles around the reservoir. There is no camping allowed. Parking is $5 with an extra $2 fee for a dog. Dogs have to be on the leash around the lawn but they are allowed off the leash in remote parts of the park. The park is open from 8 a.m. to dusk.

Wildcat Canyon Regional Park

Wildcat Canyon Regional Park is a 2,429-acre (983 ha) East Bay Regional Parks District park located within the city limits of Richmond in Contra Costa County in the San Francisco Bay Area of California. It includes a portion of Wildcat Canyon as well as a portion of the adjoining San Pablo Ridge, and is directly connected to the more heavily used Tilden Regional Park.

1923 Berkeley, California fire Conflagration that consumed 640 structures, including 584 homes

The 1923 Berkeley Fire was a conflagration that 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.

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. Two minor lakes or ponds lie along the creek: Jewel Lake and Lake Anza. The latter was enlarged by the construction of a small dam in the mid-20th century. An active tectonic fault, the Wildcat Fault, runs the length of the canyon. Wildcat Canyon was named for the mountain lions which used to be fairly common in the area. The southern end of the canyon adjacent to the city of Berkeley was incorporated into Tilden Regional Park in the 1930s and remains a major recreation area for local residents. Another regional park, Wildcat Canyon Regional Park, is situated at the northern end of the canyon.

San Leandro Creek

San Leandro Creek is a 21.7-mile-long (34.9 km) year-round natural stream in the hills above Oakland in Alameda County and Contra Costa County of the East Bay in northern California.

Briones Regional Park

Briones Regional Park is a 6,117-acre (24.75 km2) regional park in the East Bay Regional Park District (EBRPD) system, located in the Briones Hills of central Contra Costa County of the San Francisco Bay Area in California.

Lake Chabot Regional Park

Lake Chabot Regional Park is a regional park located in the southern Berkeley Hills in Alameda County, California. It is part of the East Bay Regional Parks system.

Las Trampas Regional Wilderness

Las Trampas Regional Wilderness is a 5,342-acre (21.62 km2) regional park located in Alameda and Contra Costa counties in Northern California. The nearest city is Danville, California. Las Trampas is Spanish for the traps, or the snares. The park belongs to the East Bay Regional Park District (EBRPD).

Robert Sibley Volcanic Regional Preserve

Robert Sibley Volcanic Regional Preserve is located in the Berkeley Hills of the East Bay region of the San Francisco Bay Area, California. The park is part of the East Bay Regional Parks District (EBRPD), covers 928 acres (3.76 km2), and lies east of Oakland, partly in Alameda County and partly in Contra Costa County. It can be entered from Oakland via Skyline Boulevard, or from Contra Costa County via Old Tunnel Road.

Wildcat Creek (California)

Wildcat Creek is a 13.4-mile-long (21.6 km) creek which flows through Wildcat Canyon situated between the Berkeley Hills and the San Pablo Ridge, emptying into San Pablo Bay in Contra Costa County, northern California.

Pinole Creek

Pinole Creek is a stream in western Contra Costa County, in the East Bay region of the San Francisco Bay Area, California.

Oakland Hills, Oakland, California

Oakland Hills is an informal term used to indicate the city neighborhoods lying within the eastern portion of Oakland, California. The northernmost neighborhoods were devastated by the Oakland firestorm of 1991.

Briones Hills Location in the San Francisco Bay Area, California, United States

The Briones Hills form a low mountain range in western Contra Costa County, in the East Bay region of the San Francisco Bay Area, California, United States.

The Claremont Shale is a Miocene epoch geologic formation in the Berkeley Hills of the East Bay region of the San Francisco Bay Area, California.

Moraga Formation

The Moraga Formation or Moraga Volcanics is a Pliocene epoch volcanic geologic formation in the Berkeley Hills of the East Bay region of the San Francisco Bay Area, California.

The Orinda Formation is a Miocene epoch geologic formation in the Berkeley Hills of the East Bay region of the San Francisco Bay Area, California.

References

Notes
  1. "Berkeley Hills". Geographic Names Information System . United States Geological Survey . Retrieved 2009-05-04.
  2. Reports of Explorations and Surveys for a Railroad from the Mississippi River to the Pacific Ocean...1853-54, Volume 5, p.139-40, United States Army Corps of Engineers, 1856
  3. Oakland East Quadrangle 1973, USGS Topographic Map
  4. Las Trampas Ridge Quadrangle 1968, USGS Topographic Map
  5. San Francisco 15-minute Quadrangle 1895, USGS Topographic Map
  6. Robles, Marcos, and F. S. Chapin. “COMPARISON OF THE INFLUENCE OF TWO EXOTIC COMMUNITIES ON ECOSYSTEM PROCESSES IN THE BERKELEY HILLS.” Madroño, vol. 42, no. 3, California Botanical Society, 1995, pp. 349–57, http://www.jstor.org/stable/41425082.
Sources