Mount Tamalpais State Park

Mount Tamalpais State Park, though it includes the east peak, lies mainly to the south and west of the mountain and extends to the ocean. (See also Mount Tamalpais.) A variety of plant communities is found here, including northern coastal scrub, coastal prairie, mixed evergreen forest, redwood forest, chaparral, coastal sage scrub, and riparian. Several of the communities are particularly noteworthy.

To the east of Steep Ravine there is a rather extensive grassland with elements of both the coastal and Central Valley prairies. Purple needlegrass, Nassella pulchra, occurs here on serpentine-derived soils in almost pure stands.

Along Redwood Creek is one of the better remaining examples of a riparian community in the County. Among the species found here are big-leaf maple, Acer macrophyllum, willow, Salix spp., Oregon ash, Fraxinus latifolia, red alder, Alnus oregona, and California bay, Umbellularia californica. Sargent cypress, Cupressus sargentii, occurs on serpentine soils in the park.

Six rare plants are found in the park: Arctostaphylos hookeri ssp. montana, Arctostaphylos virgata, Ceanothus masonii, Cirsium hydrophilum var. vaseyi, Dichondra donnelliana and Erysimum franciscanum var. franciscanum.

Most of the park coastline is rocky outer coast. The area is entirely underlain by rocks of the Franciscan formation, and there are serpentine outcrops.

Integrity: Portions have been developed for park purposes and there are a number of trails; however, much of the area is relatively undisturbed.

Use: Research, educational, observational, present.

February 1978