We will designate critical habitat, if prudent and determinable, for the rufa red knot under the Endangered Species Act. This migratory shorebird travels between breeding areas in the central Canadian Arctic and wintering areas in parts of the United States (primarily Texas, Louisiana, Georgia, Florida, South Carolina, and North Carolina, and some in Mississippi), the Caribbean, and southern South America along the coast of Chile and Argentina. Most migrate along the Atlantic coast of the United States, where they may be found from Maine to Florida. This species is listed as a threatened species.