At the eastern fringe of the San Francisco Bay Region, Mount Diablo - elevation 3,849 feet - stands alone on the edge of Califonia's Great Central Valley. The Coast Range at this point consists only of low hills, none high enough to block the view from the upper slopes of the mountain. As a result the view is spectacular.

The View From the Top
Many visitors to Mount Diablo head straight for the summit to enjoy the famous view. Summer days are sometimes hazy, and the best viewing is often on the day after a winter storm. Then, you can look to the west, beyond the Golden Gate Bridge, to the Farallon Islands; south-east to the James Lick Observatory on Mount Hamilton at 4,213 feet elevation; south to Mount Loma Prieta in the Santa Cruz Mountains at 3,791 feet elevation, north to Mount Saint Helena in the Coast Range at 4,344 feet elevation, and still farther north to Mount Lassen in the Cascades at 10,466 feet. North and east of Mount Diablo the San Joaquin and Sacramento Rivers meet to form the twisting waterways of the Delta. To the east beyond Califomia's great central valley, the crest of the Sierra Nevada seems to float in space.

Early History
In 1851, the mountain top was selected as the starting point for a survey of the public domain. Ignoring the excitement of the Cold Rush, Leander Ransome and his men erected a flagpole at the summit of Mount Diablo and began to extend the base and meridian lines that we use to this day in our official land surveys. As a matter of fact, Mount Diablo base and meridian lines are referred to in legal descriptions of real estate throughout two-thirds of California and parts of Nevada and Oregon.
For more information on the survey, see article in our Publications On-Line.
For other information on early history and legends on how the mountain was named, see Cultural History

The Mountain Welcomes Visitors
Toll roads up the mountain were open in 1874, and for many years there were two stages every day connecting Walnut Creek and Danville with Mountain House, a 16-room hotel about three miles from the summit. The hotel offered "all conveniences" and was known for its excellent food. Wedding ceremonies were a frequent occurrence at the hotel, and celebrities from all over Europe and America were among the visitors. Business at the hotel declined after the summit observation platform burned in 1891, and shortly thereafter the hotel burned down as well. The toll roads were closed and for many years there was no legal means of public access to the mountain. The toll roads were reopened in 1915, however, so that the view from the top was once again available to all.
See Mountain House Hotel and Mount Diablo Scenic Road History as well as Publications On-Line for more information.

Formation of the Park
In 1921, a parcel of land on the mountain was designated a state park, and much of the rest of the mountain was declared a game refuge. Standard Oil placed a ten-million candlepower aerial navigation beacon on the summit in 1928. The beacon was so powerful that it could be seen by ships 100 miles at sea. Finally, in 1931, the state acquired more land for Mount Diablo State Park, and the park was formally dedicated.

For information on the building atop the mountain, see Summit Museum..
For a summary of the history of Mount Diablo, see article.