Agreement to Safeguard the Biodiversity of Mount Tamalpais

FOR IMMEDIATE RELEASE

Contact: Amina Sharma, California Native Plant Society, (916) 694-0118, asharma@cnps.org
Mike Swezy, Marin Conservation League (415) 485-6257
Barbara Salzman, Marin Audubon Society (415) 924-6057  

May 6, 2025, MARIN, Calif.—Plaintiffs California Native Plant Society (CNPS), Marin Conservation League (MCL) and Marin Audubon Society, have reached a settlement with the Marin Municipal Water District (MMWD) in the case of “California Native Plant Society, et al vs. Marin Municipal Water District.” 

The settlement concerns two pilot projects that would have dramatically expanded bicycle and e-bike access to the MMWD watershed without environmental review. The pilot projects challenged in the case were: Trail Sharing Pilot Program: authorizing bicycles on nine single-track trails for two years; and E-Bike Class I Trial: authorizing Class I e-bikes to ride on the 90 miles of roads and fire roads open to bicycles, as well as on the single-track trails authorized by the Trail Sharing Pilot Program, also for two years. 

In September 2024, MMWD’s board of directors approved a pilot project that would have allowed Class 1 electric bicycles to access all trails open to conventional bicycles and extended a “pilot trail sharing” project that would have opened several single-track trails to bicycles. MMWD’s use of exemptions from rigorous environmental review under the California Environmental Quality Act was challenged by the three environmental groups as being in error. A court issued a preliminary injunction prohibiting MMWD from implementing the pilot programs pending resolution of the merits. 

MMWD has agreed to withdraw approval of the Trail Sharing Pilot Program and not reinstate it without a review under the California Environmental Quality Act (CEQA). “Mt. Tam is such a special place, both beautiful and rare—a hotspot of biodiversity and rare plants,” says CNPS Marin Chapter board member David Long. “It’s no wonder so many of us want to hike, ride, and play on this gorgeous mountain. We’re pleased that MMWD is taking the time for thoughtful planning with the community. Environmental review is how we achieve an appropriate balance to both enjoy and protect the natural places we cherish.” 

 In addition, MMWD agreed to rescind the resolution authorizing the E- bike Class I Trial and adopt a Revised E-Bike Pilot Program. This revised program will monitor threats to wildlife and invasive plants and volume of bike usage. MMWD will also conduct visitor surveys and improve incident reporting.  

 “Studies have shown that bats hear and react to the high frequency sounds emitted by e-bikes,” says Barbara Salzman, President of Marin Audubon Society. “The new Pilot Program will include a study of the impact of e-bikes on bats by installing acoustic detectors near selected roads that are likely habitat for bats and hiring a bat biologist to oversee a study.”  

The Marin Municipal Water District manages most of Mount Tamalpais, which includes some of the most biologically diverse land in California—recognized by inclusion in the United Nations-designated Golden Gate Biosphere. Noteworthy plants include the Mt. Tamalpais manzanita (Arctostaphylos montana ssp. Montana), Tamalpais oak (Quercus parvula var. Tamalpaisensis), Tamalpais jewel flower (Streptanthus batrachopus), and Marin manzanita (Arctostaphylos montana ssp. Montana).  

“We look forward to working with stakeholders to develop a sustainable plan for carefully increasing bicycle use on watershed lands in a way that fully protects the mountain’s special natural resources,” says MCL Board President Mike Swezy.  

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The California Native Plant Society is a statewide nonprofit organization that protects California’s native plants and their natural habitats through science, education, stewardship, gardening, and advocacy. CNPS has more than 13,000 members and 36 chapters supporting its mission throughout California and Baja California, Mexico. Learn more at cnps.org. 

 Marin Conservation League, a nonprofit organization, has been preserving, protecting, and enhancing the natural assets of Marin County for 90 years. Learn more at marinconservationleague.org. 

 Marin Audubon Society is a 501©(3) non-profit organization and a chapter of National Audubon Society working to protect native wildlife and their habitats through advocacy, habitat acquisition and ownership, stewardship, education, and science. Find out more about Marin Audubon Society and our work at marinaudubon.org.