San Bruno Mountain Watch's mission is to preserve and expand the native ecosystems of San Bruno Mountain, in perpetuity. Our goal is to conserve all undeveloped land on San Bruno Mountain as natural open space. We work with local landowners, donors, and government officials to ensure the protection of lands that are eligible for development.

For over 45 yeas, Mountain Watch has been fighting to keep the mountain wild and natural, and much of it is now preserved in the San Mateo County San Bruno Mountain Park. However, we continue to work towards preserving tracts of land that are still eligible to be built upon. Creating an expanded open space network will connect people and wildlife in northern San Mateo County to the existing San Mateo County Park. 



In 2015, San Bruno Mountain Watch was instrumental in arranging the donation and conservation of 3.25 acres of an inland sand dune on San Bruno Mountain's western slope. This land was added to the San Mateo County Park on the mountain and is now preserved. However, some of the remaining land on the sand dune is privately owned and eligible for development, despite the presence of the federally endangered Lessingia plant (Lessingia germanorum) and a Native American shellmound/burial ground. San Bruno Mountain Watch has been working with local officials and landowners to save this crucial habitat. We have also already begun native habitat restoration on the sand dune, with more ecological restoration work is planned for the future. Read more about the sand dunes.




In 2015, Mountain Watch Board Member Del Shembari helped to arrange for San Bruno Mountain to be identified as a “Priority Conservation Area” or PCA by the Association of Bay Area Governments (ABAG). This certification will be crucial in obtaining government funding for future conservation and restoration projects in the future.






Mountain Watch has identified the following locations for preservation and is actively working to preserve them:

The Upper Brisbane Acres is approximately 110 acres of undeveloped open space above the City of Brisbane with several parcels being privately owned. These parcels are rich with native grasses and wildflowers, provide opportunities for hiking, and are a vital habitat for two of the three federally listed endangered butterflies. Most importantly, they encompass a fully functioning habitat with high biodiversity. 


The San Bruno Elfin Butterfly in caterpillar stage.

Brisbane Quarry is 140 acres of aggregate quarry. It’s home to the endangered San Bruno Elfin Butterfly (Callophrys mossii bayensis) and it's host plant the Broadleaf Stonecrop (Sedum spathulifolium) that has colonized the upper benches of the quarry. To the periphery of the quarry is prime habitat for the Mission Blue and Callippe Silverspot butterflies. The lower portion of this property is frog and wetland habitat. The quarry has a huge potential as a water resource through runoff and existing springs. Our goal is to exclude this property from development and restore its biodiversity.





Callippe Hill and surrounding areas are to the east of San Bruno Mountain and are surrounded by housing developments that have encroached on critical butterfly habitat. We include in this 75 acres all undeveloped areas in and around the Northeast Ridge Development, Peking Handicraft property, Levinson property, PG&E marsh area and lands bordering Guadalupe Canyon Parkway and east of Carter Street. All of the open areas surrounding this area are critical habitat and flight corridors that keep vital butterfly habitat from being fragmented. The area is within walking distance of San Francisco public transportation and is a key connector between the mountain and the Brisbane Baylands. Mountain Watch is working to protect all undeveloped land in this area.


Crocker Industrial Park, Guadalupe Creek and the Old Ranch Road Trail to the Dairy Ravine include approximately 300 acres and a 2.5 mile trail that loops around many of the Crocker Industrial Park businesses. This trail, which includes the stream at Cypress Lane that is home to the Pacific chorus frogs (Pseudacris regilla), is the focus of the Guadalupe Valley Stewards, an ongoing restoration program in partnership with the City of Brisbane and local businesses. One of the top priorities of the program is to daylight and restore more of the urban creeks in Guadalupe Valley in order  to improve  their water quality before they enter the Brisbane lagoon and the bay, and increase the ecological value of Crocker Park through native plant landscaping.


Icehouse Hill and Upper Brisbane Baylands includes over 400 acres of grasslands and wetlands as well as the sites of the Machinery & Equipment business, Mission Blue Nursery, and the drainage channel to the Bay. Icehouse Hill is Callippe Silverspot habitat. The Mission Blue Native Plant Nursery is toward the southern end of this area. 

Brisbane and Baylands Circle Trail This area includes Tunnel Road, Lagoon Way, Beatty Way, Alanna Way, Harney Way, and the San Francisco Bay Trail, including the east and west sides of Highway 101. Our hope is to complete pedestrian and bicycle trails that connect Tunnel Road to Lagoon Way, which would then connect to the Brisbane portion of the Bay Trail. Tunnel Road also connects Bayshore Blvd. and central Brisbane to a potential trail through the railroad tunnel to Crocker Park. This will all connect with the Caltrain stop on Tunnel Road and the SamTrans bus stop in Brisbane. 


Sign Hill Park, South San Francisco City is 44.7 acres of undeveloped open space with three privately owned parcels on the west side of the hill. Over 70 native plants have been documented on the Sign Hill site. Our immediate goal is to acquire these three remaining parcels not already included in the park.

Sign Hill is a treasured San Mateo County landmark and nationally registered historic site. Less known is its stunning biodiversity and the rare value of its native Franciscan grassland habitat. As habitat for two rare and endangered species, the Callippe silverspot and Mission blue butterflies, the hill is a vital part of “… the largest, intact, healthy grouping of grassland habitat in the Bay Area...” according to Bay Area local Jake Sigg, California Native Plant Society guru.

The north side of the hill is a rich, diverse grassland habitat, never grazed by cattle. The eastern slopes are home to the federally endangered Mission Blue butterfly, that was recently adopted as the official butterfly of South San Francisco. Farther west is a stunning colony of Hummingbird Sage. The eastern parcel, with its Mission Blue butterfly habitat, is currently being considered for development. In an effort of cooperation, the developer has shared preliminary plans to put 20 houses on the site, including several going up the eastern ridge of the hill toward the famous sign.

San Bruno Mountain Watch is talking with planners, council members and possible funders with the goal of purchasing this parcel, as well as the two others, in order to save them. We are teaming up with Friends of Sign Hill to build active local support for safeguarding these valuable parcels from development.

To learn more about Sign Hill, read Kamala Silva Wolfe's article in the Peninsula Progress (scroll down to bottom of page).