The Martha Property Saved as Open Space

By Eva Buxton, Conservation and Invasive Species Chair (retiring)

After half a century of preservation efforts, 110 acres of land at the tip of the Tiburon Peninsula is now public open space. Marin County, the San Francisco-based non-profit Trust for Public Lands, and the local grassroots group Tiburon Open Space (TOS), announced in September 2024 that they had completed the $42.1 million deal to buy Easton Point, known as the Martha property, from the locally owned Martha Co. to be managed by the County. The purchase of the property prevented the building of 43 luxury mansions on the site.

The property, which abuts Marin County’s Old St. Hilary’s Open Space Preserve (OSH), now creates a 232-acre parcel with hiking trails, rare species, and panoramic views of the Bay Area – from the Richmond Bridge, East Bay Hills, San Francisco skyline, Angel Island, the Golden Gate Bridge to Mt. Tamalpais. The main trail on the property, the Ridge Fire Road, connects to the 5-mile Tiburon Ridge Trail that starts at the western portion of Ring Mountain to the north.

Part of the Martha property is a serpentine knoll, the most valuable portion both for the developer, who proposed building three houses on the knoll, and as native habitat, supporting serpentine bunchgrass grassland (Sensitive Plant Community, California Department of Fish and Wildlife (CDFW)) and endemic serpentine plants. As a Tiburon resident and also having peer-reviewed an earlier document describing the site when working as an environmental consultant (around 2000), I was familiar with its vegetation. At the suggestion of TOS, I surveyed the property in 2013 and subsequently commented on the Final EIR (Environmental Impact Report)for the proposed development, the last one of many CEQA documents for the site, on behalf of CNPS, emphasizing the sensitivity of the habitat and the presence of Marin Dwarf Flax (Hesperolinon congestum (FT/ST/CNPS Rank 1B) and Serpentine Reedgrass (Calamagrostis ophitidis) (CNPS Rank 1B). Habitat for four other special-status species that grew within 100 – 200 feet of the boundary with OSH preserve – Tiburon jewelflower (Streptanthus glandulosus ssp. niger) (FE/SE/CNPS Rank 1B), Tiburon Paintbrush (Castilleja affinis ssp. neglecta) (FE/ST/CNPS Rank 1B), Tiburon Buckwheat (Eriogonum luteolum ssp. caninum) (CNPS Rank 1B), and Carlotta Hall’s Lace Fern (Aspidotis carlotta–halliae) (CNPS Rank 1B) – exists on the Martha property but were not observed during surveys.

As a result of the presence of sensitive vegetation on the serpentine knoll and the lack of enough water pressure in case of a fire, the Marin County Board of Supervisors did not accept proposed mitigation and did not certify the Final EIR. According to Jerry Riessen, President of TOS, the three large, flat lots on the serpentine knoll with magnificent views went to being three cramped lots on sloping land with no views near Paradise Drive at the base of the property, making for a big decrease in valuation of the land. The Martha property went up for sale. My comments on behalf of CNPS were, therefore, to a great extent, the reason the Martha property was saved from development (J. Riessen, personal communication).

The financial dealings of the acquisition of the Martha property were complicated. The final amount owed by Marin County was $29.2 million to be collected from Belvedere and southern Tiburon taxpayers, who in the November 2022 election voted 79% in favor of a 30-year, $335 Measure M parcel tax to fund a bond sale. Some of the funds came from the County’s Measure A sales tax collected to support parks and open space, as well as from grants and private donations.

Some housing advocates have criticized the Martha property preservation efforts, saying that about 85% of Marin is protected for open space or agricultural uses, thus not agreeing with those that suggest that Marin is too “built out” to accommodate California’s regional assessment and mandate of about 14,000 new housing units countywide by 2031. Some voiced opposition, stating “there is a housing crisis, not an open-space crisis,” and expressing disappointment that the County’s last budget allocated more than twice as much money to open-space expenditures compared to affordable housing.

My personal concern is providing adequate public access to the property. Hopefully this beautiful and botanically valuable piece of land will be easily accessible to everyone, not only to Belvedere and Tiburon residents. If so, the collective dream of all who have worked so hard for several decades, especially Jerry Riessen, will come true: “Martha will be open to all and forever!”