San Bruno Mountain is a unique island of biodiversity in the heart of the Bay Area. This ecological treasure is home to several endangered species, dozens of rare plants, year round springs and creeks, ancient native oak groves, and 5,000-year-old Native American village sites. San Bruno Mountain is also the last viable remnant of the Franciscan bioregion that once covered San Francisco and is listed by renowned Harvard biologist E. O. Wilson as one of the world's 18 biodiversity hotspots in need of immediate preservation.
The goal of our stewardship program is to restore and conserve additional acres of the mountain each year to ensure the survival of the endangered species and retain the whole mountain as a thriving ecosystem. We do this by eradicating invasive nonnative plants and replanting native seedlings grown in our Mission Blue Nursery.
Follows is a partial list of areas of the mountain that we are currently doing restoration work in:
Buckeye and owl canyons
This part of the mountain, north of downtown Brisbane, represents some of the most sensitive habitat on the mountain for the endangered Callippe Silverspot and Mission Blue butterflies. Saved by a Mountain Watch grassroots effort and a California State bond measure in 1989, the land is owned by the California Department of Fish and Wildlife, and represents some of the most beautiful regions of the mountain. Stewardship efforts focus on restoring the native grassland habitat of the butterflies that are under threat from invasive plants and scrub succession.
Near the bottom of Owl Canyon is a .5-acre habitat for Mission Blue butterflies that Mountain Watch volunteers have carefully restored over years. The area is home to Lupinis formosus or “summer lupine”. Mission Blue butterflies will live their entire life cycle on this plant which is one of three lupines present on San Bruno Mountain. The summer lupines grow in moist areas and are favored by the butterflies in drought years when other types of lupines may dry out.
The Bog Trail region at the top of San Bruno Mountain
The wetlands in the area of the Bog Trail in the "saddle" of San Bruno Mountain are known regionally for their high diversity of rushes, sedges and other wetland plants. This freshwater wetland plant community lies between two of the headwater creeks of Colma Creek and is the last known plant community of its kind left on the San Francisco peninsula.
As recently as the 1970s, the Bog Trail region was the home of the endangered red-legged frogs and endangered San Francisco garter snakes. The bog is being restored as habitat for these species with the hope that they may be re-introduced at some time in the future.
Tucked behind a parking lot in Guadalupe Valley's Crocker Industrial Park is a small stream and wetland that has been lovingly restored by volunteers. The valley was once a mix of grassland and wetland, drained by multiple tributaries that fed into a salt marsh mingling with the San Francisco Bay. A joint project with the City of Brisbane, this gem is also a Pacific chorus frog habitat, ringing with delightful "ribbits"! Guadalupe Valley Stewards meet on Tuesday mornings to keep this area clean of debris and invasive plants. Watch our award-winning video about this wetland below.
Watch this video to learn more about Guadalupe Valley.