The Bonytail Chub

From U.S. Fish and Wildlife Service, Mountain-Prairie Region:

The bonytail chub was once found in many states, including Arizona, California, Colorado, New Mexico, Utah, and Wyoming. This fish species experienced the most abrupt decline of any of the long-lived fishes native to the main-stems of the Colorado River system and, because no young individuals have been found in recent years, has been called functionally extinct. Bonytail chubs were one of the first fish species to reflect the changes that occurred in the Colorado River basin after the construction of Hoover Dam; the fish was extirpated from the lower basin between 1926 and 1950.They may still be found in the Green River of Utah and perhaps in the larger Colorado River water bodies. Gila elegans was added to the US list of endangered species on April 23, 1980.

Photo Credit: Kevin Kappenman / USFWS