Due to the sensitivity of the habitats and the endangered species, the refuge is not open to unsupervised use by the public.
Marin Islands is closed to the public due to the sensitivity of the habitat and species present, however, there are occasional volunteer opportunities Marin Islands National Wildlife Refuge encompasses two islands, East Marin and West Marin, and the surrounding submerged tidelands. West Marin Island supports the largest heron and egret rookery in the San Francisco Bay Area. Nesting species on the island include great egrets, snowy egrets, great blue herons, and black-crowned night herons. East Marin Island supports a variety of native plants and provides critical nesting material and rest sites for the nearby colony. Submerged tidelands around the islands support a variety of resident and migratory water birds such as surf scoter, black oystercatcher, diving ducks, and osprey. The refuge was established in 1992 to protect migratory species, including the heron and egret nesting colony, protect and restore suitable habitat for the colony, and protect the tidal mud flats and unique island ecosystem.