The Fairfield Osborn Preserve is a 460-acre (1.86 km2) nature reserve situated on the northwest flank of Sonoma Mountain in Sonoma County, California. There are several plant communities within the property, oak woodland being the dominant type. Other habitats include chaparral, native clump grassland, marsh, coastal scrub and riparian zone. A diverse fauna inhabits this area including black-tailed deer, coyote, bobcat and mountain lion; moreover, there are abundant avifauna, amphibians, reptiles and insects. The flora is extremely diverse including many native trees, shrubs, grasses, lichens and mosses. Copeland Creek and its tributaries drain the preserve as they wend their way down steep ravines toward eventual discharge to the Laguna de Santa Rosa. The property was originally a Spanish Land Grant holding and is now owned and managed by Sonoma State University, who uses it as a research base and as an educational tool for the general public. An understated natural trail system weaves through the property to provide access to creek canyons, ridges and marshy areas. The preserve is situated at elevations 1,600 to 1,900 feet (488-579 m) above sea level and features a landscape riddled with basalt exposures that betray the volcanic prehistory of Sonoma Mountain.