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Peak Health

Peak Health

You can access the latest information on the health of Mt. Tamalpais in our 2023 Peak Health report. We are in the process of updating the Peak Health section of our website, so some information in these pages may still reflect our first 2016 Measuring the Health of a Mountain report. Thanks for your patience. 

REGISTER NOW for an upcoming presentation of findings from the latest update! June 20, 2024, 6:30-8:00 pm online. Register to receive a link to join the webinar.

Bird Species
Native Animal Species
Plant Species
Acres Studied
Wildlife Acorn woodpecker | Photo by Nagarajan Kanna


Wildlife are found in every habitat type on the mountain, where they may be grazers, predators, or prey.

Plants Serpentine Barrens | One Tam Image Library


Plant communities, and their arrangement on the landscape, are the foundation of ecosystem health.

Landscapes Landscapes | Photo by Mason Cummings


Most of Mt. Tam’s plant communities are suffering the effects of climate change, invasive species, plant disease, and fire. 

An Ecological Treasure in Our Backyard

The San Francisco Bay Area is part of a nationally and internationally recognized biodiversity hotspot and part of the UNESCO Golden Gate Biosphere Reserve. Located right on San Francisco’s doorstep, Mt. Tamalpais is a vital refuge for many threatened, endangered, and special status species, and is an important link in a much larger network of interconnected open spaces, including the 195,000 acres of protected open space in Marin County that many other plants and wildlife depend upon.

The mountain’s remarkable diversity is thanks to its location near the coast, and to its varied topography, which creates a confounding array of microclimates in a relatively small space. A wide range of soils—including beautiful but harshly metallic green serpentine—create unique niches for different plant communities, and for the animals that depend upon them.  

While Mt. Tamalpais’ plants and animals live in protected open spaces, invasive non-native plants and animals, changing wildfire patterns, plant diseases such as Sudden Oak Death, and climate change still threaten their survival. One Tam partners are working together to monitor, restore, and protect the mountain so that it continues to thrive into the future. 

How Can I Help?
  • Donate: Give to support the mountain, and the projects and programs helping to care for this special place
  • Volunteer: Help restore habitats, protect wildlife, and other activities
  • Learn & Share: Join one of many educational programs hosted by One Tam partners and other local environmental organizations, and share your sightings on iNaturalist 
  • Care: Stay on designated trails to protect sensitive species and habitats, and use native or non-invasive plants for home landscaping

Measuring the Health of Mt. Tamalpais

To maintain a healthy, vibrant, and diverse Mt. Tamalpais, One Tam partners begin with understanding how key indicators of ecological health are faring, and how we can better care for this iconic and beloved place. Along with other Bay Area scientists, we have come together to try to answer the question: Is Mt. Tamalpais at peak health?

The information presented here is the result of an unprecedented collaboration among Mt. Tamalpais’ land managers, the Golden Gate National Parks Conservancy, and the scientific community to use the most current data and best expert judgment to understand and evaluate the mountain’s health. The first report, Measuring the Health of a Mountain, was published in 2016. We subsequently completed the first update in 2023, Peak Health: An Update on the Status of Mt. Tamalpais’ Ecosystems.

This guide was created to help others interested in doing their own ecological health assessments. 

The Overall Health of Mt. Tam

Fair condition, no change in trendMt. Tamalpais’ ecosystems are in an overall Fair condition. Some of the mountain’s plants and wildlife are thriving, while others are suffering the effects of invasive species, plant disease, changed fire frequencies, and climate change. However, even some of those in decline are at a point where their trajectory can still be improved. 

What’s new in this update? Since 2016, we were able to fill information gaps identified in the first report including bats, bees, and California giant salamanders. We used new data sources, such as the Marin Countywide Vegetation Map and community-sourced data from iNaturalist. We also incorporated updated information about our ecosystems’ vulnerability to climate change. The condition and trend of many species or groups, such as lichens remain largely unknown.

We did not establish a trend in the overall condition for Mt. Tam between 2016 and 2022 because of the addition of new indicators since 2016, an expanded geography, and a major new vegetation mapping effort that parses those communities differently than before. In addition, some indicators improved while others declined or did not see a change in condition. 

Learn more through the links to the WildlifePlants, and Landscapes health indicator assessments above, or download the full report here.

Check our calendar for upcoming public events where you can learn more about the mountain’s ecosystems.

Many People, Working Together