The Presidio features a 300-acre historic forest planted by the U.S. Army beginning in the 1880s. There are about 60,000 trees in the park today. The park also shelters 13 distinctive plant communities supporting 300 native plant species, ranging from wildflowers to oak woodlands. Sixteen species 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.
It's land is home to a variety of mammals, reptiles, aquatic species, and invertebrates. These include native gray fox, the San Francisco alligator lizard, the three-spined stickleback fish, and 30 kinds of butterflies. Bring binoculars! More than 300 bird species are seen at the, including year-round residents like Anna's Hummingbirds, Red-shouldered Hawks, Great Egrets, and Great Horned Owls to migratory species like Violet-green Swallows and Red-throated Loons. El Polin Spring and Crissy Marsh are great places for birdwatching.