Lassen Peak, 181 miles (291 km) away, is occasionally just visible over the curve of the earth.
No indigenous people have publicly claimed to have built the Big Horn Medicine Wheel.
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 an isolated upthrust peak of 3,849 feet (1,173 m), 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 of which is the other half of the double pyramid, North Peak, nearly as high in elevation at 3,557 feet (1,084 m) and about a mile northeast of the main summit.
The peak is in Mount Diablo State Park, a state park of about 20,000 acres (8,000 ha).
The park was the first public open space of a complex—according to Save Mount Diablo—now including 38 preserves, including nearby city open spaces, regional parks, watersheds, that are buffered in some areas with private lands protected with conservation easements.