Post contributed by Lisa Crovo Dion
You might not have realized it at the time, but if you’ve ever driven through San Francisco en route to the Golden Gate Bridge, you have passed right by (and above) one of the city’s last surviving natural lakes, and the only natural lake in the entire 80,000-acre Golden Gate National Recreation Area.
This jewel, tucked behind the multi-million dollar homes that line tony Lake Street, was once the home to San Francisco’s original inhabitants, the Ohlone.
But, sadly, a century of neglect rendered the once pristine wilderness a shameful blight.
Building projects, run-off from the highway leading to the bridge, urbanization, pollution, and dumping left the area an overgrown wasteland, groaning under the weight of invasive species and blighted by everything from construction debris to escaped pet store fish and reptiles.
Locals thought they were doing a good thing by releasing pets into the lake — goldfish, turtles, a five-foot sturgeon, and even an alligator (!) were found in the beleaguered lake. These critters forced out the native wildlife and damaged the lake’s ecological system.
A few years ago though, Mountain Lake (located in the Presidio of San Francisco), received a much-needed rehab stint and a dramatic makeover.
Led by biologist Jonathan Young, a team from San Francisco State University worked alongside the Presidio Trust to help birds nest, grow plants, and restore the lake to its former glory. The massive project involved shifting over 6,000 cubic yards of earth for landscaping, and carefully replanting more than 30 species of plants, each with its own special requirements.
Some keys to the project’s success were grazing Boer goats, which have cleared the underbrush naturally, the dredging of the lake to remove debris, and reestablishing native species.
The end result is four acres of restored wetland, filled with native plants and animals like the California red-legged frog, the Pacific chorus frog, and Westland pond turtles.
Another critical factor was clean water. High quality water helps the returning plants, marine life, and animals thrive. A specialist company, Clear Creek Systems was contracted to extract, filter, treat with polymers, then pump back the lake water. This multi-step process transformed murky dredgings into crystal clear water.
The main aim of the project was to get people to reconnect with nature. Plant lovers will find wild strawberries, cow parsnips, cinquefoil and pink honeysuckle; landscape lovers will enjoy a completely ‘wraparound’ natural space; and animal lovers can discover native species and observe how they live.
For recreation, Mountain Lake offers a labyrinth of walking/biking trails, tennis courts, a “parcourse” with stations to work out at, and a children’s play area.
In addition to the environmental benefits, nearby Lake Street residents will see a huge reduction in the mosquitos. As well as being snapped up by reptiles, insects like the Damselfly and their young feast on mosquito larvae.
The area is already sustaining a far richer biodiversity of species, and the riparian, scrub, woodland, and wetland habitats will be restored to close to their natural state.
To learn more about the is remarkable transformation, visit
If you decide to visit, grab a bite at Ashley’s, a clean, attractive cafe nearby on California St @ 7th Ave with outdoor seating, great coffee and tasty sandwiches. Try the bulgogi, a tasty Korean classic or my favorite, the onigiri, Japanese rice balls with various fillings, wrapped in seaweed.
Photos by Lisa Crovo Dion