We’re revitalizing the Presidio’s wetlands, grasslands, sand dunes, and creeks.
Shaped by geology and climate, the land we now call the Presidio was once blanketed with ecologically vibrant wetlands, grasslands, sand dunes, and creeks.
Over centuries, people shaped the land: from the Ohlone who used fire to regenerate seed to the U.S. Army which developed a military post that impacted these habitats, leading to the loss of plants and wildlife.
Despite the changes, natural habitats remain – and are being expanded through the practice of ecological restoration and land stewardship. The Presidio Trust, the National Park Service, and the Golden Gate National Parks Conservancy – with thousands of volunteers – are bringing back natural systems.
These case studies explore some our major efforts.
Tennessee Hollow is the Presidio’s largest watershed. It encompasses 270 acres in the eastern Presidio, about 20 percent of the park. It begins with springs near the Presidio Gate. The waters then flow north through three seasonal creeks before blending into the salt water of San Francisco Bay.
Over decades, the U.S. Army greatly altered this area by creating buildings roads, and landfills, burying much of the creek underground.
Since the Presidio has been a national park site, we’re restored more than 50 acres of native habitat here. Serpentine grasslands have been expanded at Inspiration Point. Native wetland habitat has been restored at El Polin Spring and Thompson Reach. And tidal salt marshes have been brought back to life at Crissy Marsh and Quartermaster Reach Marsh.
Mountain Lake is one of San Francisco’s last natural lakes and the only natural lake in the Golden Gate National Recreation Area. For millennia, San Francisco’s first people, the Ohlone, were inhabitants. And it was here in 1776 that Spanish Captain Juan Bautista de Anza’s expedition camped as they scouted where to build their military fort or “presidio.”
Mountain Lake later went through rough times. In 1939, a highway to the Golden Gate Bridge was built, shrinking the lake’s size. Runoff from the nearby golf course and highway spoiled water quality. Locals released unwanted pets, pushing out native wildlife.
With help from scientists, academic institutions, and volunteers, Mountain Lake is rebounding. In 2013 and 2014, we removed polluted soil and invasive species. Native species are now being reestablished – from underwater plants to the Western pond turtle and Pacific chorus frog.
Much of San Francisco was once a sand dune ecosystem that supported a diverse group of plant and animal species. Some of these, such as the now endangered San Francisco lessingia, were found only here.
Although small remnants of sand dunes persisted during the Presidio’s Army era, more 70 acres of sand dunes have been restored throughout the Presidio since it became a national park site. You can experience dune restoration along the Mountain Lake Trail and the Batteries to Bluffs Trail.