In addition to the main campus, the university also owns and operates two off–campus study sites for students of the natural sciences. The first site is the 411-acre (166 ha) Fairfield Osborn Preserve, located on nearby Sonoma Mountain.[25] The second site is the 3,200-acre (1,300 ha) Galbreath Wildlands Preserve in Mendocino County.[26] Both offer opportunities for research and hands-on education to students of the university.