It is a hands-on guide to learning about the natural environment of California. Subjects covered include California natural history and geology, native plants and animals, California's freshwater resources and ecosystems, forest and rangeland resources, conservation biology, and the effects of global warming on California's natural communities. The Handbook also discusses how to create and use a field notebook, natural resource interpretation, citizen science, and collaborative conservation and serves as the primary text for the California Naturalist Program.