Mount Diablo is a mountain of the Diablo Range, in Contra Costa County of the eastern San Francisco Bay Area in Northern California. It is south of Clayton and northeast of Danville. It is an isolated upthrust peak of , visible from most of the San Francisco Bay Area. Mount Diablo appears from many angles to be a double pyramid and has many subsidiary peaks. The largest and closest is North Peak, the other half of the double pyramid, which is nearly as high in elevation at , and is about northeast of the main summit.
The mountain is within the boundaries of Mount Diablo State Park, which is administered by California State Parks.
Geography
The summit is accessible by foot, bicycle, or motor vehicle. Road access is via North Gate Road or South Gate Road. Also you can hike in various places in Mount Diablo.
Mount Diablo State Park
The peak is in Mount Diablo State Park, a state park of about . The state park was the first public open space established on or near the peak. According to the non-profit Save Mount Diablo, there are now varied types of protected lands on and around Mount Diablo that total more than . These include 38 preserves, such as nearby city open spaces, regional parks, and watersheds, which are buffered in some areas with private lands that have been protected by conservation easements.
Viewshed
On a clear day, the Sierra Nevada range is plainly visible from the summit. The best views are after a winter storm; a snowy Sierra shows up better, and summer days are likely to be hazy. Lassen Peak, away, is occasionally just visible over the curve of the earth. Sentinel Dome in Yosemite National Park is visible, but Half Dome is hidden by the 8000-foot ridge at 37.755N 119.6657W. Eight bridges are visible, from left to right (southwest to northeast): San Mateo, Bay, Golden Gate, San Rafael, Carquinez, Benicia, Antioch, and Rio Vista.
Countless peaks in the state are taller, but Mount Diablo has a remarkable visual prominence for a mountain of such low elevation. Its looming presence over much of the Bay Area, delta, and Central Valley, and good visibility even from the Mother Lode, all key regions during the gold rush and early statehood, made it an important landmark for mapping and navigation. The summit is used as the reference datum for land surveying in much of northern California and Nevada.
Claims that the mountain's viewshed is the largest in the worldor second largest after Mount Kilimanjaroare ill-founded. It does boast one of the largest viewsheds in the Western United States and played a key role in California history.
Cultural history
Mount Diablo is sacred to many California Native American peoples. According to Miwok mythology and Ohlone mythology, it was the point of creation. The local peoples of the area traditionally had a variety of creation narratives associated with the mountain. In one surviving narrative fragment, Mount Diablo and Reed's Peak (Mount Tamalpais) were surrounded by water; from these two islands the creator Coyote and his assistant Eagle-man made Native American people and the world. In another, Molok the Condor brought forth his grandson Wek-Wek the Falcon Hero, from within the mountain.
Earliest names
About 25 independent tribal groups with well-defined territories lived in the East Bay countryside surrounding the mountain at time of European contact. Their members spoke dialects of three distinct languages: Ohlone, Bay Miwok, and Northern Valley Yokuts. The Chochenyo-speaking Ohlone from Mission San Jose and the East Bay area, call the mountain , meaning "at the dawn of time". Further inland, the Nisenan of the Sacramento Valley call it , "dog mountain"; because, as Nisenan elder Dalbert Castro once explained, it's "the place where dogs came from in trade". A Southern Sierra Miwok name for the mountain is , and a Northern Sierra Miwok name is .
It has also been suggested that another early Native American name for the mountain was or , but there is no evidence to confirm the assertion. According to Indian historian Bev Ortiz and Save Mount Diablo: "The name was made up in 1866 — with no real Native American connection — referred to the California Legislature's Committee on Public Morals, and tabled. It resurfaced as a real estate gimmick in 1916 with a supposed new translation, "Laughing Mountain", attributed without documentation to Diablo area Volvon Indians.
Most of Mount Diablo, including its peak, was within the homeland of the early Volvon (sometimes spelled Wolwon, Bolbon or Bolgon), a Bay Miwok–speaking tribe. As early as 1811, Spanish colonists referred to the mountain as ("High Hill of the Volvon") or sometimes .
