Endangered and Threatened Wildlife and Plants; Final Designation of Critical Habitat for the Rio Grande Silvery Minnow

We, the U.S. Fish and Wildlife Service (Service), designate critical habitat for the Rio Grande silvery minnow (Hybognathus amarus), a species federally listed as endangered under the authority of the Endangered Species Act of 1973, as amended (Act). This species, also referred to herein as silvery minnow or minnow, presently occurs only in the Rio Grande from Cochiti Dam downstream to the headwaters of Elephant Butte Reservoir, New Mexico, approximately five percent of its known historical range. Critical habitat overlays this last remaining portion of occupied range. It encompasses 262 kilometers (km) (163 miles (mi)) of the mainstem Rio Grande from the downstream side of the State Highway 22 bridge crossing the Rio Grande immediately downstream of Cochiti Dam, to the crossing of the Atchison Topeka and Santa Fe Railroad near San Marcial, New Mexico.