This summer, One Tam partners are working with local fire agencies to plan more prescribed burns for the fall—part of a long-term effort to reduce wildfire risk while supporting the health and diversity of Mt. Tam’s landscapes.
Fire has always had an important role in these landscapes and shaped how native species thrive. Signs of a carefully planned prescribed burn's positive impact emerged this spring, as one rare bloom seemed to be putting on a show:
It couldn't have been a more perfect spring Mt. Tam morning—wildflowers peeking above dew-covered grass, sun slowly warming the freshest smelling air. We had come to count the points of palest pink that seemed to be everywhere. There were thousands.
Oakland star-tulip (Calochortus umbellatus) is a California endemic species of lily that grows mostly in the Bay Area. It blooms March to June in a range of white to pink to lavender, and can be spotted growing both in open areas and under shrubs, and even in serpentine soils. And it's one of the rare species monitored by our One Tam Conservation Management team.
The team mapped patches of the species occurring in grassy areas around Deer Park Fire Road in Mt. Tamalpais State Park back in 2019. Conservation Management Program Manager David Greenberger led a resurvey effort this year, curious how the species might respond to a prescribed burn conducted there the previous fall, opening the place up from encroaching shrubs. The increased exposure to sunlight and reduced competition from reducing shrub cover, plus the addition of nutrients to the environment from ash, could contribute to a good year for Calochortus. Beyond that, chemical cues during and after fire often have stimulating effects on the growth and flowering of bulbs like those in the Calochortus genus.
It was more than an impression that these grasslands seemed a galaxy's worth of star-tulips. We observed an order of magnitude more individuals at each location, totaling 28,535 across three patches in 2025 compared to 1,080 in 2019.
As the One Tam partners look ahead to future prescribed burns, this spring’s bloom offers a powerful reminder of what’s at stake—and what’s possible. Beneficial fire can be a tool for renewal, helping landscapes flourish and rare species like the Oakland star-tulip return in breathtaking numbers. Each season of observation adds to our understanding, guiding how we care for this place so it can continue to thrive for generations to come.
The One Tam partnership mobilizes the resources of the Parks Conservancy, National Park Service, Marin Water, Marin County Parks, and California State Parks to ensure a vibrant future for Mt. Tamalpais. Find out more about the partnership here.
