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Dexter NFHTC 1984 year class reared at Floyd Lamb State Park in Nevada (Abate et al. 2002). Larval RBS have been collected at several spawning locations in Lake Mead since 1995. In 2002, using fin ray sections, several fish were aged at 6-10 years, indicating recent recruitment to the Lake Mead population (Abate et. al 2002). Currently, the larger Lake Mohave population provides the benchmark for the success of RBS recovery throughout the basin. The recovery effort, as reflected by the intense management program to restore the RBS population in Lake Mohave, relies on augmentation of the existing population with hatchery reared fish. Lake Mohave The largest aggregation of RBS in the Colorado River resides in this mainstem reservoir. The population represents the majority of the genetic diversity remaining in the species, and is essential to the recovery of RBS. The Lake Mohave population consists of a declining number of old adults, estimated to be at least 50 years of age. Adult population estimates have ranged from 60,000 individuals in the 1980s to fewer than 2,500 today (T. Burke. Bureau of Reclamation, Pers. comm. 2002). The Lake Mohave Native Fishes Work Group, in a multi- agency conservation effort with the U. S. Fish an d Wildlife Service, has implemented an augmentation program to maintain the Lake Mohave population since 1992. Rearing strategies include the use of federal, state, county and city captive rearing facilities, in addition to off-channel coves to effectively hold and spawn adults, hatch and rear wild caught larvae, juveniles, and sub-adults. Using these many strategies, the Biological Opinion goal (USFWS 1994) to stock 50,000 RBS in Lake Mohave was met in 2001. The current management approach for captive rearing is based on the collection of wild spawned larvae from Lake Mohave adults during the spring spawning season. The larvae are transported to Willow Beach NFH for rearing. Fingerlings are then 10