The James V. Fitzgerald Marine Reserve is located in Moss Beach, along the San Mateo County coast, about halfway between Pacifica and Half Moon Bay. Established in 1969 to protect the area’s rich marine habitat, the reserve is the most visited of all San Mateo County parks.
While the 180-acre reserve contains bluff-top trails through a century-old Cypress grove, tide pools are the main attraction at Fitzgerald. Scientists have discovered more than 25 new invertebrate and plant species here.
To see Fitzgerald Marine Reserve at its best, plan your visit at low tide. The 3-mile stretch of beach and rocky intertidal is a geological wonder and one of the most biologically diverse regions along the Pacific coast. Naturalists estimate there may be as many as 1,000 different forms of animal at plant life at Fitzgerald. In number of species, Fitzgerald Marine Reserve is one of the greatest concentrations of intertidal life in the world. Look for seaweeds, algae, snails, limpets, barnacles, mussels, crabs, anemones, sea stars, chitons, urchins, abalone, nudibranchs, small fish and shore birds.
Harbor seals are found year-round at Fitzgerald Marine Reserve. Elephant seals, sea lions, otters and whales are occasional visitors.
Geologically, Fitzgerald features bedrock of Montara Mountain Granodiorite, part of the huge “Salinian Block” that lies west of the San Andreas fault, which is about 7 miles northeast of the reserve. Over the past 29 million years, movement along the San Andreas has pushed this rock hundreds of miles from the south.
At shoreline is primarily Purisima formation, layered marine sediments overlaying the bedrock. This tan and gray siltstone was created during the Pleistocene era and is 7- to 3-million years old. Fossils, mainly invertebrates, can be found in this layer. Upturned layers of this siltstone have eroded to form the tide pools for which Fitzgerald is famous. The syncline at the north end of the reserve is formed by the Seal Cove fault, part of the San Gregorio fault zone.
The crumbling cliffs above the beach are marine terrace layers that are approximately 100,000 years old.
The oldest fossil found at Fitzgerald is a baleen whale estimated to be between 2- and 5-million years old. A prehistoric walrus bone found at Fitzgerald and donated to The Smithsonian Institute, is estimated to be from the Pleistocene era, 4 million years ago.
Artifacts of Native American inhabitants ancestral to the Ohlones, people who were here at least 10,000 years ago, have been found at Fitzgerald. A relic of a cutting stone, estimated to be 5,700 years old, found at Fitzgerald by archeologist Mark Hylkema, was donated to the San Mateo County Historical Museum.