Gulf of Mexico Bryde’s whales (Balaenoptera edeni) were listed as endangered under the Endangered Species Act (ESA) by the National Marine Fisheries Service (NMFS) effective April 15, 2019 (84 FR 15446). On October 22, 2021, NMFS published a final rule that revised the listing of Gulf of Mexico Bryde’s whales to reflect the scientifically accepted taxonomy and nomenclature of the species (86 FR 47022). The revised common name for this species is Rice’s whale and the scientific name is Balaenoptera ricei. The ESA requires that critical habitat be designated to the maximum extent prudent and determinable at the time a species is listed (16 U.S.C. 1533(a)(3)(i)). NMFS concluded that critical habitat was not yet determinable for the Rice’s whale at the time of listing. However, NMFS indicated that they anticipated critical habitat would be determinable in the future given on-going research. NMFS, therefore, announced in the final listing rule that they would propose critical habitat in a separate rulemaking. This rule finalizes designation of critical habitat for the endangered Rice’s whale as one specific area within the Gulf of Mexico that extends from the Texas-Mexico border in the west to the Florida Keys in the east and lies between the 100m and 400m isobaths. NMFS will consult with the Department of Defense to assess any potential national security impacts as a result of the critical habitat designation.