This preserve encompasses approximately 1000 acres and contains extensive areas of intertidal habitat used by a variety of shorebirds, wading birds and other species. It is part of the USFWS designated critical habitat for Piping Plover. The landscape is dominated by tidal flats and seagrasses which support prey that attract many species of herons, egrets, terns, spoonbills, gulls and shorebirds. There are also small islands of coastal prairie in the upland areas and relict oyster reefs within the adjacent shallow waters.
The tidal flats and adjacent habitats within this area were set aside for the conservation of Piping Plover and other shorebirds through the Texas General Land Office Adopt-a-Habitat Program in October 1996 and is currently managed through a management plan cooperatively developed by the USFWS, GLO, Texas Parks and Wildlife and National Audubon Society. The area is named in honor of the late Mollie Beattie, the director of the US Fish and Wildlife Service in 1995.