Fairfield Osborn Preserve

Fairfield Osborn Preserve
Copeland Creek with basalt armor in channel, Fairfield Osborn Preserve
Map
LocationSonoma Mountain, Sonoma County, California, United States
Area450 acres
Elevation411 to 701 meters above sea level
Established1972
Governing bodySonoma State University

The Fairfield Osborn Preserve is a 450-acre nature reserve situated on the northwest flank of Sonoma Mountain in Sonoma County, California. There are eight plant communities within the property, oak woodland being the dominant type.[1] Other communities include chaparral, Douglas fir woodland, native Bunch grass, freshwater marsh, vernal pool, pond and riparian woodland. The flora is extremely diverse including many native trees, shrubs, wildflowers, grasses, lichens and mosses. A diverse fauna inhabits this area including black-tailed deer, coyote, bobcat and an occasional mountain lion; moreover, there are abundant avifauna (including some neotropical migrants), amphibians, reptiles and insects.

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, devolving to private ownership and eventually given to The Nature Conservancy; the preserve is now owned and managed by Sonoma State University as a research and education site. 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 1,350 to 2,300 feet (411 to 701 meters) above sea level and features a landscape riddled with basalt exposures that betray the volcanic prehistory of Sonoma County.[2][3] The climate at the Preserve is mild, with most rainfall occurring in the winter months and with some influence of the Pacific Ocean providing moderating temperatures and some marine fog on early summer mornings.[4]

  1. ^ Larry Serpa and Lynn Lozier, Fairfield Osborn Preserve: Natural History and Ecology (1981)
  2. ^ Santa Rosa Quadrangle, Fifteen minute series, USGS Quadrangle Map, U.S. Government Printing Office, Washington DC (1958)
  3. ^ "Geologic Map of the Santa Rosa Quadrangle". State of California, Department of Conservation. 2007.
  4. ^ Environmental Impact Report for the Petaluma General Plan, Earth Metrics Inc. for the city of Petaluma and California State Clearinghouse (1986).