Native Plant Communities

The Presidio is a refuge for once-abundant and diverse ecological communities that have been all but lost in the urban Bay Area. The park’s remnant natural areas contain some of the last examples of San Francisco’s once extensive dune and serpentine native plant communities. The Presidio is home to 13 different native vegetation communities supporting 300 native plant species, ranging from wildflowers to oak woodlands. Sixteen are rare or endangered, including five protected by the Endangered Species Act. Examples include the San Francisco lessingia and the Presidio clarkia (wildflowers found in only two locations worldwide), and the Raven’s manzanita. The Presidio’s Vegetation Management Plan defines long-range plans for natural areas and other open spaces.

Wildlife

The park’s habitats support a wide range of wildlife. More than 200 bird species ranging from year-round residents like Anna’s Hummingbirds, Red-shouldered Hawks, and Great Egrets to migratory species like Violet-green Swallows and Red-throated Loons can be spotted here. Migratory invertebrates such as monarch butterflies also visit the Presidio. The park is home to mammals, reptiles, and aquatic species, including the native gray fox, the alligator lizard, and the three-spined stickleback fish. Research studies increase our understanding of wildlife here and how to protect them. Recent studies have examined songbirds, mammals, and bees.

Geology and Soil

Some of the key stories of the Bay Area’s varied geology can be told in the Presidio, which is located in a seismically active zone. The park features an unusual blend of geologic formations. Resources include the Colma formation dunes and the serpentine outcrops and bluffs at Inspiration Point and south of Crissy Field. The region’s most spectacular remnant of serpentinite (the state mineral) dramatically faces the Golden Gate. Nearby, one can still walk amidst ancient sand dunes that once covered 14 square miles of San Francisco.

Water

Freshwater played an essential role in the establishment of the Presidio and the City of San Francisco. In the Presidio’s early days, El Polin Spring (in the Tennessee Hollow Watershed), Mountain Lake, and Lobos Creek provided enough water to meet the needs of the military and surrounding City. In the 1890s, the City’s demand outpaced Lobos Creek’s supply and alternate sources for the City were developed. Lobos Creek still serves as the Presidio’s primary water source, meeting nearly 80 percent of demand. Lobos Creek, Mountain Lake, El Polin Spring, and Crissy Field also support ecologically diverse and abundant wildlife habitat.