Diablo Foothills Regional Park, Regional park in Contra Costa County, California.

Diablo Foothills Regional Park covers 1,060 acres (4.3 km2) of the northern Diablo Range, west of Mount Diablo and Mount Diablo State Park, in Contra Costa County; Walnut Creek is the nearest city. The photograph shows a dry, stony hillside of bare earth and low dark scrub, with one broad-crowned tree on the skyline. The park borders Castle Rock Regional Recreation Area to the east and Shell Ridge Open Space to the north.

The East Bay Regional Park District assembled Diablo Foothills Regional Park from land west of Mount Diablo and Mount Diablo State Park, in the northern Diablo Range. The park was later bordered by Castle Rock Regional Recreation Area to the east and Shell Ridge Open Space to the north; together the three properties hold 18,000 acres of protected land.

The name comes from the Diablo Foothills of the northern Diablo Range, the belt of low hills west of Mount Diablo where the park lies. The East Bay Regional Park District holds the land as public open space, and its 1,060 acres adjoin Castle Rock Regional Recreation Area and Shell Ridge Open Space, together 18,000 acres. Visitors reach it from Walnut Creek, the nearest city.

Diablo Foothills Regional Park lies west of Mount Diablo and Mount Diablo State Park, with Walnut Creek the nearest city. It borders Castle Rock Regional Recreation Area on the east and Shell Ridge Open Space on the north; the three together hold 18,000 acres of parkland. Enter from the Walnut Creek side and carry water, as the hillside ground is dry and stony.

The park covers 1,060 acres (4.3 km2) and, together with Castle Rock Regional Recreation Area to the east and Shell Ridge Open Space to the north, forms 18,000 acres (73 km2) of contiguous protected land. The nearest city is Walnut Creek, and Mount Diablo and Mount Diablo State Park lie to the east.