Mt. Tam

Check out what's new with One Tam!


Special Events

Bioblitz season is here!

What's a bioblitz? A community science event where we document every plant and animal species we see. Hone your naturalist skills, learn to use the iNaturalist smartphone app, and contribute valuable data about the Bay Area’s biodiversity!

May 5: Slide Ranch >>

May 11: Bootjack >> 

June 9: San Geronimo Ridge >>

Member hikes

Wednesday, May 8, 12:30-2 pm: Nature Journal Workshop! This month's member "hike" is a nature journaling workshop with artist and naturalist John (Jack) Muir Laws! Enhance your drawing, observation, and journaling skills. 

Volunteer and Internship Opportunities

Check out these drop-in volunteer opportunities:

• Wildlife image cataloging – April 24May 10, May 17, May 22
• Restoration projects – May 19

There's a lot more at! Check our calendar for event details and more opportunities offered by One Tam partners.


Roy's Redwoods

A One Tam team is exploring opportunities to improve the visitor experience and ecological health of Roy's Redwoods Open Space Preserve. You can come and learn more about what makes this preserve special at a May12 Field Day - meet our team and tell them what you love about Roy's!


New Library Parks Pass Program

The County of Marin, Marin County Free Library, and One Tam are partnering on a new program that increases access for residents for whom entrance fees may pose a barrier to visiting parks. Library card holders can check out a pass for free entry to beautiful local parks, and a backpack full of information to help explore them. Available at all 10 branches of the Marin County Free Library and Bookmobile starting April 9.

Conservation Science

New Work Studying Pollinators Underway

Stemming from the Mt. Tam Science Summit held last fall, MMWD and San Francisco State University are set to begin inventorying pollinators, primarily bees, on the mountain this spring. This will be the first time this part of Marin has ever been surveyed for pollinators. The field season should start at the beginning of March, but may be delayed by rain. There will be a number of opportunities to volunteer with this project, including specimen processing events. Stay tuned on

New Inventory of Mt. Tam's Bats Begins

One of the information gaps identified during the 2016 Mt. Tam health assessment was that we don’t know very much about bats on the mountain. Marin potentially supports up to 16 species of bats. This year’s study includes a number of components that will increase our understanding of bats and their ecology in Marin, and will employ several sampling methods including acoustic monitoring and mist netting. Information collected will include bat activity and species identification. The overarching goals of the study are to understand the relationships of bats and bat diversity to the landscape, the distribution of reproductive bats, and to provide insights on roosting ecology and roost selection in both summer and winter. This kind of data will contribute to our understanding of the diversity, health, and distribution of bats in the region, and inform management around protecting these species from disease.