The McLaughlin Reserve is one of few sites in California that protects unusual serpentine habitats. Chemically hostile to most plants, serpentine deposits cover one third of the reserve, creating islands of rare and endemic plants that have adapted to these harsh soils along with numerous associated endemic insects. Where there are non-serpentine soils, the vegetation shifts suddenly to more typical coast range habitats, including riparian woodland, blue oak woodland and savannah, grassland, and chaparral.