By Kristin Jakob and Laura Lovett

Tiburon’s Ring Mountain is now known to be a rare biological island, home to several rare plants including one species unique to that site. However, it went through some rough times before it was preserved for the public to enjoy. Upon its founding in 1974, CNPS Marin Chapter became active participants in the campaign to save Ring Mountain. Its significant role in the story of the Preserve includes early and continuing advocacy, a long history of educational outings, and the compilation and maintenance of a plant species checklist. Last year, in conjunction with Marin County Parks, it established the Ring Mountain Wildflower Docent Program to help visitors learn about this unique site.

Ring Mountain: Photo by Laura Lovett

Tiburon Mariposa Lily, a Rare Endemic

Ring Mountain is probably best known for the Tiburon mariposa lily, Calochortus tiburonensis, whose entire population is restricted to the serpentine rock outcrops in the grasslands of the Preserve’s upper slopes. Its existence was brought to scientific light by Chapter member and amateur botanist Dr. Robert (Bob) West. Bob, a regular leader of plant and mushroom field trips for the Marin Chapter, resided in Corte Madera near the northern foot of Ring Mountain. In June of 1971, he observed and photographed a lily he didn’t recognize while hiking on the ridge. The cryptic coloration of the flowers and foliage matches the tones of the drying grasses among which it grows, effectively camouflaging the plant and delaying its discovery. Bob showed his photos of the lily to Florence Youngberg of Ross, who in turn showed them to Annetta Carter, a Research Associate at the University of California Herbarium in Berkeley, who then brought them to the attention of Albert Hill at the UC Berkeley Botanic Garden. Albert had a special interest in the genus Calochortus and in 1973 proceeded to describe and name the new species in Vol. 22 of Madroño, the quarterly journal of The California Botanical Society.


Notes written on 22 June 1972 by Phyllis Ellmman – Photo courtesy of the Belvedere-Tiburon Landmarks Society

Serpentine and Other Habitats

The mountain is home to several other rare plant species: serpentine reedgrass (Calamagrostis ophitidis), Oakland star tulip (Calochortus umbellatus), marsh star tulip (Calochortus uniflorus), Tiburon paintbrush (Castilleja affinis ssp. neglecta), Tiburon buckwheat (Eriogonum luteolum var. caninum), Marin dwarf flax (Hesperolinon congestum), and marsh zigadene (Toxicoscordion fontanum). These and several other plants found on Ring Mountain are considered serpentine endemics, having been found (at least to date) only growing in soil derived from serpentine rock. This soil type is high in minerals such as chromium and nickel that are generally toxic to plants, and low in primary plant nutrients. The soil is commonly waterlogged in winter and very dry in summer except along watercourses. These conditions favor adapted native plants and are inhospitable to most invasive introduced species, so this habitat can reward visitors with spectacular floral displays and great botanical interest.

Serpentine grasslands cover nearly fifty percent of Ring Mountain’s acreage, with nonnative grasslands dominating the lower slopes with deeper soils. There are also patches of mixed evergreen forest, areas of coyote brush scrub, along with seeps and freshwater marshes that support moisture-loving species. This diversity of habitats provides for a particularly rich array of plants.

From Grazing to Preservation

The land we now know as Ring Mountain Preserve was originally part of an 8,000-acre land grant called Rancho Corte Madera del Presidio, deeded to Irish immigrant John Reed in 1834. The Reed family and descendants owned much of Tiburon Ridge and used it for grazing up until the 1900s, when development was started on the lower slopes.

In the 1940s, the US Army took over the property, bulldozed large terraces out of the slopes, and pushed serpentine soil to places it wasn‘t before. In the 1950s, the highest part of the mountain served as the location for a large 16-inch gun installation. Some of this damage was repaired and bunkers were removed when the Army left, but the terracing and red chert (brought in for drainage) platforms remain.

In the 1960s, Thomas Deffebach, descendent of the original land-grant family, sold 427 acres along the top of the ridge to developers Ring Mountain Ltd. The move to build on the remaining portion of this rare habitat galvanized Marin County’s conservation organizations to campaign to preserve it.

Marin Chapter member and Tiburon resident Phyllis Ellman served on a newly-formed Ring Mountain Advisory Committee to review development plans put forward. Phyllis was a tireless advocate for protection of this property. She led untold field trips on the mountain to show others the location’s unique flora, encouraging them to support the campaign to preserve it.

Phyllis Ellman standing by the trail marker – Photo courtesy of the Belvedere-Tiburon Landmarks Society

The Nature Conservancy (TNC) entered the picture in 1980 when they launched a campaign called California Critical Areas Program, a push to evaluate and identify eleven sites around California that represented optimal examples of particular habitats and worthy of preservation. Ring Mountain was chosen as a unique example of serpentine grassland. TNC initiated negotiations with the developers to purchase some or all of the unbuilt portion. The first parcel purchased was the 74-acre strip that runs from Paradise Drive to the top of the mountain. The developers concluded that it was unstable enough as to be unbuildable and sold it to TNC for $400,000.

In need of funding for their development plans, Ring Mountain Ltd. received a loan from The Nature Conservancy; in exchange for five years of interest TNC took title to another 42 acres at the top of the mountain. TNC specifically chose the area where the Tiburon Mariposa lily grows. As part of the deal, TNC obtained management authority over the remaining 311 acres for the next five years.

Ring Mountain Ltd. got approval to build 50 houses on 64 acres in pockets adjacent to existing development, then tried to sell the land and development approval to a bank which would not accept it with the TNC management lease attached. Ring Mountain Ltd. promptly gave all but 50 acres to TNC to clear the title, adding 261 acres to the total acreage that became Ring Mountain Preserve. Because of potential damage from earlier landslides, TNC left the responsibility to remediate the unstable sections with Ring Mountain Ltd. but put up the $450,000 required to do the work. CNPS Marin Chapter contributed $4,400, donated by our members to our Ring Mountain Fund.

This beautiful and singular property had been torn up by motorcyclists and dirt bikers over many years, leaving deep scars. In addition, it had been used as an illegal dumping site. TNC biologist Lynn Lozier was made preserve manager. Together with community volunteers, she started the work of putting up fencing and gates and removing and repairing the damage. Twenty-eight truckloads of trash were hauled away from the east side alone.

Ring Mountain Preserve was dedicated on April 23, 1983. The Nature Conservancy named the main trail for Phyllis Ellman in recognition of her tireless work to help secure the land for conservation and public use. On November 13, 1995, The Nature Conservancy transferred ownership to the newly-formed Marin County Open Space District, which presently maintains this gem.

Consider joining CNPS Marin Chapter in preserving Ring Mountain by participating in the Ring Mountain Wildflower Docent Program.