Berkeley Hills

The Berkeley Hills are a range of the Pacific Coast Ranges, and they look over the northeast side of the valley that includes the San Francisco Bay. These hills used to be called the "Contra Costa Range/Hills" after the old Spanish name Sierra de la Contra Costa. But when the towns of Berkeley and the University of California were created, people who study maps and geography changed the name to Berkeley Hills. Today, the Berkeley Hills are an important part of the landscape, giving a beautiful view of the bay and the surrounding areas.

Geology

The Berkeley Hills are next to two important faults—the Hayward Fault on the west and the Wildcat fault on the east. The highest points are Grizzly Peak, which is 1,754 feet tall, Round Top, an old volcano that reaches 1,761 feet, and William Rust Summit, standing at 1,004 feet.

Vollmer Peak, which is 1,905 feet tall, is often thought to be part of the Berkeley Hills. However, it is actually on the nearby San Pablo Ridge. Vollmer Peak was named after August Vollmer, the first police chief of Berkeley, and used to be called "Bald Peak" and "Rocky Mound".

Because of loose dirt on the slopes and the effects of faults, the Berkeley Hills can sometimes experience landslides, especially after heavy rain.

Development

The west slope of the Berkeley Hills has many homes, mostly single-family houses, except for the land belonging to the University of California, Berkeley. The streets here are usually narrow and follow the shape of the land. Three streets—Marin Avenue, Moeser Lane, and Potrero Avenue—go straight up toward the top of the hills. Other roads wind up through the valleys. Grizzly Peak and Skyline Boulevards run along the very top of the ridge. Many people living in these neighborhoods are among the more well-off residents of Berkeley and Oakland.

The east slope of the Berkeley Hills is mostly kept natural or only partly built on, with 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 include Wildcat Canyon Regional Park, Tilden Regional Park, Sibley Volcanic Regional Park, Huckleberry Botanic Regional Preserve, Redwood Regional Park, Anthony Chabot Regional Park, Lake Chabot Regional Park, and Cull Canyon Regional Recreation Area. Additional parks like Claremont Canyon Regional Preserve and Temescal Regional Park are lower on the western slopes, while Las Trampas Regional Wilderness lies lower on the eastern slope above Danville.

The Berkeley Hills have several tunnels. The Claremont Tunnel carries water from an EBMUD treatment plant in Orinda to areas west. The Berkeley Hills Tunnel is used by the Yellow 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.

Usage

People often call the part of the Berkeley Hills near Oakland the "Oakland Hills". While this sounds common, it isn't quite right as a proper name. Maps don't always agree on where the Berkeley Hills end to the south, but they do show the hills going well into the northeastern part of Oakland. These hills don't follow any political borders—they are just a natural feature, like how "San Francisco Bay" isn't limited to just the city of San Francisco. The ridge continues south through Oakland and San Leandro all the way to a place called Castro Valley, and it keeps going in a geological sense past a line called the Hayward Fault. In the area from East Oakland to Castro Valley, most maps call this part the "San Leandro Hills".

The northern edge of the Berkeley Hills is clearer. Most maps, including those from the USGS, show the name "Berkeley Hills" covering the whole ridge up to a place called the mouth of Wildcat Canyon in Richmond. The eastern sides of the Berkeley Hills are completely outside the city of Berkeley and lie in Contra Costa County.

Sometimes people use the term "East Bay Hills", but it's not very specific. It could mean any of the ranges east of the Bay, from the Berkeley Hills all the way to the Diablo Range and everything in between.

Ecology

The Berkeley Hills are a place with many different plants and animals. They are part of the Pacific Coastal Region of California and the San Francisco Bay area. Many parts of the hills are covered in grass, especially on the slopes that face southwest. Long ago, animals like cows and sheep lived there and ate the grass. In the 1930s, people removed these animals from some areas to protect the water and create parks. This change allowed bushes to grow in place of some grasslands.

The hills are home to many animals, including birds, black-tailed deer, coyote, ground squirrel, striped skunk, western terrestrial garter snake, gray fox, bobcat, and red-tailed hawk. Sometimes, mountain lions can be seen in the oak woodlands. The area also protects special animals like the San Francisco tree lupine moth, Alameda whipsnake, Callippe silverspot, and Bay checkerspot. Birds such as the northern harrier, American kestrel, prairie falcon, and turkey vulture visit the grasslands each year looking for food.

Climatic effects

The Berkeley Hills change the weather in the area because of their height. During summer, a layer of fog and clouds from the ocean stays low, usually below 2,000 feet, and the hills block this fog. This creates a warmer area on the east side compared to the west side. The wind that brings the fog usually splits when it reaches the hills, creating different wind directions north and south.

In winter, fog can sometimes stay on the east side of the hills, and occasionally moves around them from the north. The hills also affect rain; when wind blows straight at the hills during storms, the air rises, cools, and creates more rain on the west side, leaving the east side drier. Very cold storms can sometimes leave wet snow on the highest points. In the past, strong, dry winds in spring and fall have sometimes caused fires, including big fires in 1923 and 1991 that damaged homes and plants in Berkeley and Oakland.
Main articles: 1923 Berkeley Fire and 1991 Oakland firestorm