Mount Diablo State Park is a state park in California, USA.

View SW across the park from near the summit of Mt. Diablo

Table of contents
1 Geography
2 History
3 Natural History
4 Facilities
5 External links
6 Reference


The park surrounds and includes Mount Diablo, an isolated 1173 meter (3489 feet) peak that is visible from many places in the surrounding region. It is located south of the town of Clayton, California and north-east of Danville, California. It is accessible only by car. It is approximately 8000 hectares (20000 acres) in area, and its elevation varies from approximately 90 meters (300 feet) to the summit height.


Mount Diablo is sacred to many Native American peoples; according to Miwok mythology, it was the point of creation. In 1851 it was selected by Colonel Leander Ransom as the reference point for the surveying of the region, and much of California, Nevada and Oregon was surveyed from this base. Toll roads up the mountain were created in 1874 by local hoteliers, and an aerial navigation beacon was erected at the summit in 1928. After an initial purchase in 1921, the state of California acquired enough land in 1928 to create the present state park. Many improvements were carried out in the 1930s by the California Conservation Corps.

Summit building, Mt. Diablo

Natural History

The mountain is largely composed of hard red Franciscan rock that is sedimentary in origin and therefore rich in fossils. The park's vegetation is mixed oak and grassland country with extensive areas of chaparral. There are stands of Knobcone pine, Foothill pine, and Coulter pine (for which the park marks the northern extreme of the range), and a number of endemic plant species. Commonly seen animals include Black-tailed Deer, California Ground Squirrels, Fox Squirrels and Gray Foxes; many other mammals including Mountain lions are present. It is the chief remaining refuge for the endangered Alameda Whipsnake.


A road reaches the summit of the mountain, where there is an observation building with a visitor's centre. There are numerous hiking trails and some paths available for mountain biking and horse-riding. Camping facilities are available within the park.

External links


  • Information from the California State Parks leaflet on Mount Diablo State Park, issue 8/01, 2000.