A developed hardwood forest and mixed community of Valley Oak (Quercus lobata) and Coulter pine (Pinus coulteri) thrives on the slopes of Chews Ridge. The ridge unusually supports extensive areas of savanna with large valley oaks, with many patches of open grassland than other peaks in the Santa Lucia Range. The predominant rock types include pre-cretaceous schist, very small ultrabasic outcrops, and Miocene sandstone.