Rancho Monte del Diablo

Rancho Monte del Diablo (Devil's Mount Ranch in Spanish) was a 17,921-acre (72.52 km2) Mexican land grant in present-day Contra Costa County, California given in 1834 by Governor José Figueroa to Salvio Pacheco.

[1] The name "Monte del Diablo" means "thicket of the devil" in Spanish.

The grant covered the area from the Walnut Creek channel east to the hills, and generally from the Mount Diablo foothills north along Lime Ridge to Avon on the Carquinez Strait of the Sacramento River, and included present day Concord and parts of Pleasant Hill.

In 1827, Pacheco was serving as a senior civil servant at the Pueblo of San José.

[3] With the cession of California to the United States following the Mexican-American War, the 1848 Treaty of Guadalupe Hidalgo provided that the land grants would be honored.