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Mount Diablo State Park

Mount Diablo State Park

Summit Rd, Walnut Creek, CA 94598, United States


Mount Diablo is an Eastern Diablo Range Peak in Contra Costa County, Northern California's South San Francisco Bay Area. It's southeastern to Clayton and northwest to Danville. The elevation of upthrust is isolated from the San Francisco Area, at 1,173 m (3,849 m). Mount Diablo appears to be a double pyramid in many ways and has several subsidiary peaks, of which the other half is the highest and nearest one, North Mountain, almost as high at 3557 feet (1084 m) and about 1 kilometer northeast of the main mountain. Mount Diablo in San Francisco Bay Area is a 20,000 hectare state Park located in Contra Costa County. The park protects Mount Diablo, an imposing mountain that is only 1,173 meters tall, and yet overlooks the city, offering fantastic views from its top that can be seen from 181 miles to the north, on clear days. The park protects Mount Lassen.

To many Americans, Mount Diablo was believed to be the site of origin for the Miwok Indians. At Rock City and elsewhere in the area, signs of Native American activity on the mountain today is seen with grinding trolling in the soil, demonstrating where the Miwok once pounded corns and other nuts into sand. In the 1851 map of the Western United States the range played a key role, as Colonel Leander Ransom decided to start with the southern tip of the mountain. More surveys were performed at this point in much of California, Oregon and Nevada.  By 1931, when the state bought land around the lake, the preservation of the mountain began and a park had been created. During the 1930s, a number of changes were made to the town by the Civil Conservation Corps, including highways, trails, guard houses, maintenance buildings, campsites and picnic facilities. The CCC has also designed the Summit Visitor Center using stone from the peak. Now, tourists can see shells and other fossils preserved in the natural construction material. On 8 December 1941, the day after the Pearl Harbor attack, the light was switched off on Mount Diablo to avoid the use of the light by the enemy aircraft. A ceremony took place at the visitor center on Mt. Diablo on December 7, 1964 which included overhead jets and speaking dignitaries. The goal was to turn the light on again. Admiral Chester W. Nimitz, the last remaining admiral in the United States navy, came out with the switch flipping the screen. The light is on the evening of 7 December, only once a year. The founding of the Save Mount Diablo movement started in 1971 a campaign to enlarge the park and protect the mountain from construction. Since then, the park has expanded from 6,788 acres to about 20,000 acres.


Mount Diablo is quite a young geological site, which was formed about a million years ago. Among converging earthquake problems the mountain was created by a constant height, which moves the mountain more strongly by 3-5 mm each year. The top and bottom of the mountains are composed of greenstones, a 90–190 million years-old igneous material, while the sides of the mountains contain large deposits of sandstone, deposited in ancient sea beds and sunsets and fossils.

This amazing park is located near the following parks in Danville, California:

  • Danville South Park
  • Las Trampas Regional Wilderness
  • Mount Diablo State Park
  • Diablo Vista Park
  • Hap Magee Ranch Park
  • Osage Station Park
  • Sycamore Valley Park
  • Oak Hill Park

All of these wonderful parks are located just a short distance from our location, Robert Arnone CPA.





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