Due to the sensitivity of the habitats and the endangered species, the refuge is not open to unsupervised use by the public.
Antioch Dunes National Wildlife Refuge is the only national wildlife refuge in the country established to protect endangered plants and insects – the Antioch Dunes evening primrose, the Contra Costa wallflower, and the Lange’s metalmark butterfly. Created in 1980, the 55-acre refuge was once part of a larger sand dune system that stretched two miles along the southern bank of the San Joaquin River east of the City of Antioch. The sand dunes were formed by ancient deposits of glacial sands carried downriver from the Sierra Nevada. Isolation of these dunes resulted in the development of species of plants and insects that were found nowhere else in the world. Large-scale sand mining and industrial development fragmented the sand dune habitat until only a small portion of the original ecosystem remains. The refuge is comprised of two disjunct sand dune parcels, the Stamm and Sardis Units.