Blue Oak Ranch Reserve

Most of Blue Oak Ranch Reserve (BORR) lies within the Upper Sonoran Life Zone. Approximately two-thirds of the site is drained by tributaries of Arroyo Aguague, itself a tributary of Coyote Creek (via Penitencia Creek), which flows into southern San Francisco Bay.

The bowl-shaped Arroyo Aguague catchment area is characterized by steep wooded slopes and meadows, as well as open flats dotted with oaks and coyote brush. The precipitous Arroyo Hondo is heavily wooded on north- and east-facing slopes, while western and southern exposures consist of open grassland or dense chaparral patches.

Streams on the ranch support healthy stands of riparian vegetation in addition to aquatic species. They are important habitat for migratory birds and may be migratory corridors for numerous aquatic and terrestrial animal species. At least 73 vascular plant families are found at BORR, almost 80 percent of which are native. Plant communities include blue oak woodland, valley oak woodland, black oak woodland, coast live oak woodland, riparian forest, chamise chaparral, Diablan sage scrub, nonnative annual grassland, wildflower field, and native perennial grassland. Four of these are threatened plant communities: valley oak woodlands, blue oak woodlands, wildflower field, and native perennial grasslands. Blue and valley oak woodlands have become quite rare in California, and few are protected from grazing and the encroachment of suburban development as they are at BORR.

Foothill pines occur only in the Arroyo Hondo and on the slopes above its confluence with North Creek. Chaparral patches occur on many south-facing and some west-facing slopes. Grasslands are mainly dominated by exotic annuals, but some native perennial grasses are present.

BORR habitats support at least 130 species of birds, approximately 41 species of mammals, 7 species of amphibians, more 14 species of reptiles, 7 species of fish, and hundreds of species of invertebrates. BORR's streams and 17 ponds are Sensitive Aquatic Resource Areas habitats that support most of the reserve's rare species. There the river otter, California tiger salamander, foothill yellow-legged frog, and red-legged frog. BORR's riparian areas are utilized by more than ten species of neotropical migratory birds, including flycatchers, warblers, and vireos.

Photo Gallery

Contact Information
Michael Hamilton
Reserve Director
University of California
Blue Oak Ranch Reserve
302F Toyon Ave. #110
San Jose, CA 95127
Erik Viik steward

Blue Oak Website

Santa Clara County, 11.2 miles east of downtown San Jose.
Google Map

Reserve is day-use or overnight camping at this time. A network of roads gives access to most areas within the property. New facilities are currently being planned.

Plant List
ArcGIS data library; airborne and satellite imagery for Mt. Hamilton Range; Google Earth KML for boundary and local features; species lists (vertebrates and plants); bibliography; climate records for Mt. Hamilton and City of San Jose. On-site weather station in operation since August 2008; two microclimate sensor networks will be in place by March 2009.

Resident reserve director, reserve steward; campus-based faculty reserve manager.

1,319 hectares (3,259 acres)

454 - 870 m (1,489 - 2,855 ft.)
Mt. Hamilton summit: 1,280 m (4,200 ft.)

Average Precipitation
60.27 cm (23.7 in.) per year

Average Temperatures
January range: 2.5ºC (36.5ºF) to 8.8ºC (48.3ºF)
July range: 16.6ºC (62.2ºF) to 25.5ºC (78ºF)

(Both temperature and rainfall statistics were taken from the National Weather Service station atop Mount Hamilton, five miles from the reserve.)

© Regents of the University of California.