Considered one of the most biologically diverse areas in the nation, the Lower Rio Grande Valley is recognized as one of the top birding destinations in North America and is host to more than half the bird species that breed or migrate in the continental U.S. Situated at the juncture of two migratory flyways, the isolated wetlands and clay loma flats are prime habitat for songbirds, waterfowl and shore birds such as Reddish egrets, sandpipers and plovers.
In 1999, The Conservation Fund worked with private landowners and the U.S. Fish and Wildlife Service to complete the acquisition of nearly 20,000 acres as an addition to the refuge. Known as Redhead Ridge for the redhead ducks that gather here, these lands also support endangered species such as the aplomado falcon and the ocelot.
The protection of this diverse assemblage of fresh and salt water lakes, ponds, streams, marshes and lagoons, also enables the restoration of some 6,500 acres of the Bahia Grande tidal wetlands. The reflooding of this once tidally influenced area will enhance the habitat for migratory waterfowl, shrimp and fish nurseries.