Woodrats eat seeds, nuts, and berries. The meadow mouse or vole is abundant in the grassland areas of Mount Diablo. Voles make runways through the grass. They feed on grass, seeds, roots, and bark. This gopher, seen throughout Mount Diablo, also digs up lawns and gardens.
Gophers feed on roots, grasses, herbs, and seeds.
This common red-brown colored squirrel is seen on power lines and trees throughout the bay area. The fox squirrel was introduced into California and has replaced the grey squirrel over much of its range. It was introduced into Mount Diablo State Park in 1960. Grey squirrels, which were abundant on the mountain have not been seen since shortly after the fox squirrels were released. Ground squirrels are abundant in the developed areas of Mount Diablo.