Most of Mount Diablo, including its peak, was within the homeland of the early Volvon, a Bay Miwok-speaking group, and as early as 1811, the mountain was called Cerro Alto de los Bolbones (High Point of the Volvon).
About 25 independant tribal groups with well-defined territories lived in the surrounding East Bay countryside. Their members spoke dialects of three distinct languages: Ohlone, Bay Miwok, and Northern Valley Yokuts. Each tribe's leadership and culture varied and had three or four village sites, with populations numbering from 40 to 200.
Today, the mountain remains an important and meaningful place for many Native peoples, including those that live locally. As Pomo elder and doctor Mabel McKay said in 1985, "I would listen as Jim [Cooper, an herb doctor who was born in the Diablo area] told my grandmother about how sacred Mount Diablo is. He said that as long as the mountain stands is will be a sacred mountain."...Mount Diablo had profound significance for many Native California groups within its expansive view. The Julpun of the area now known as Brentwood and Byron recognized the mountain as the birthplace of the world. Hundreds of miles away in the Sierra Nevada, some Northern Miwok saw it as the place from which a supranatural being lit a previously dark landscape. Further south, the Central Miwok featured this mountain as part of their most sacred ceremonies. Wintun elder Frances McDaniel said that Wintun spiritual leaders prayed to the creator from the mountain's heights.