Cuesta Ridge Botanical Area
Map SatelliteDesignated a Botanical Area in 1969 primarily because of the unique stand of Sargent cypress, Cupressus sargentii, there are several other botanical features of interest.
Approximately half of the area is dominated by the cypress, which show varying age classes, density and type of understory. The largest recorded Sargent cypress is found here, its age estimated at between 125 and 150 years.
The remaining area is chaparral consisting primarily of Arctostaphylos spp., Ceanothus spp., and, to a lesser extent, Adenostoma fasciculatum. There are also a few barren patches.
Eight rare plants are found in the area including one, Sidalcea hickmanii ssp. anomala, which is found only here and in the immediate vicinity. Other rarities include Arctostaphylos obispoensis, Calochortus obispoensis, Carex obispoensis, Chorizanthe breweri, Cirsium fontinale var. obispoense, Fritillaria viridea, and Monardella palmeri.
Most animal species common to the central coast have been observed in or near the area but it has not been intensively studied and there is a possibility that fauna more typically associated with more northern areas is present.
Cuesta Ridge arose by uplifting, folding and faulting of a previously eroded landscape. The formation is an ultrabasic intrusive of the late Mesozoic. Rocks present are primarily serpentine, peridotite, pyroxenite, norite and gabbro. The soil derived from the serpentine is alkaline and low in essential nutrients.
Integrity: Considerable mining and prospecting for chrome and chromite have occurred in the area and there are several open pit mines which have not re-vegetated. There is a road and firebreak running through the area near the ridge.
Use: Education, observation, research. Although the area has burned at various times, it has not suffered a major burn since 1939 and thus offers an opportunity to study fire succession.
Ref: Hoover, Robert. 1970. The Vascular Plants of San Luis Obispo County, California. University of California Press, Berkeley.
September 1975
Inventory of California Natural Areas
Revision © 2009 Steven Louis Hartman