PROTECTION STATUS: Endangered
YEAR PLACED ON LIST: 1991
CRITICAL HABITAT: 1,724 river miles in the Colorado River basin designated in 1994
RANGE: Near extinction in the lower Colorado River basin; occurs in the upper Colorado River basin in the lower Yampa River, Green River, mainstem Colorado River, and lower San Juan River
THREATS: Alteration and fragmentation of habitat due to dams, altered river flow and degraded habitat from water diversion and hydroelectric projects, introduction of nonnative fishes, livestock grazing, climate change, and pollution
POPULATION TREND: The razorback sucker was once abundant throughout the Colorado River basin. It is near extinction in the in the lower Colorado River basin and extirpated from the Grand Canyon. In the lower basin, the only substantial population remaining is in Lake Mohave, and suckers are rare in all other areas, with small numbers in Lake Mead and Lake Havasu. There has not been significant natural recruitment of young fish to these populations for many decades. There are small numbers of suckers in the Green River, upper Colorado River, and San Juan River subbasins, as well as in small tributaries of the Gila River, such as the Verde River, Salt River, and Fossil Creek.