Last updated: March 24, 2022
Mountain Lake is a peaceful oasis and popular location for nature lovers, runners, and cyclists. One of San Francisco's few remaining natural lakes, the fresh waters here make life possible for plants, birds and other wildlife. Though the lake suffered serious degradation for many years, long term efforts to improve the environmental health of the area are proving effective.
Restoring Mountain Lake
Mountain Lake experienced rough times during the last 100 years. The lake was partially filled when Highway 1 was built next to it in 1939. Since then, traffic pollution has led to an accumulation of heavy metals in the water, impacting our native animal friends. Further challenges came from residents releasing aquatic pets (including an alligator) that competed with native wildlife in the lake.
With help from scientists, academic institutions and volunteers, Mountain Lake is rebounding. Thanks to an improvement in water quality, the Presidio Trust recently reintroduced the western pond turtle, pacific chorus frog and three-spined stickleback.
Native submerged aquatic vegetation has also been successfully reintroduced to Mountain Lake, a sign that things are looking up for native species. More than 65 bird species visit the site, and the area has become a living classroom for students learning about ecology.