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increase survivorship of the translocated fish. It is hypothesized that by moving fish higher up in the watershed, they will be retained longer in the LCR, have more time for growth, and nave a greater chance for survival. Background The habitat above Chute Falls is most likely within the historic range of numpback chub. Skeletal remains of Colorado pikeminnow, razorback sucker, bony tail, and humpback chub have been recovered from the Homol'ovi archaeological ruins near Winslow, Arizona (Strand 1998). Miller (1963) reported catches of Colorado pikeminnow and bony tails (G. elegans) at the base of Grand Falls in the early 1900s (-120 km above the LCR confluence). These reports suggest that a historic native fish community was well established in the LCR above Chute Falls. Until the translocation of humpback chub above Chute Falls in 2003, the only native species known to recently exist between Chute Falls and Blue Springs (at 21 km) was the speckled dace (Rhinichthys osculus). Non-native fish that been captured or observed include carp, fathead minnow (Kaeding and Zimmerman 1983), plains killifish, red shiner, black bullhead, channel catfish, rainbow trout, and green sunfish (Stone and Sponholtz, 2003). The reason humpback chub were not formerly found in recent studies above Chute Falls is unknown. Chute Falls may have been a physical barrier (Robinson et al. 1996), which implies that if humpback chub were historically above Chute Falls, local extinction occurred (e.g., environmental stochasticity) and the species was unable to successfully re-colonize. The recent translocation results (Stone and Sponholtz 2003) thus far suggest that there is suitable habitat available for humpback chub to persist above Chute Falls. The region is characterized by pool, riffle and run ,habitat; densely abundant algal communities (particularly during extended periods of base flow); and an abundant prey source (Le., aquatic invertebrates and speckled dace). Robinson et al. (1996) concluded that neither food nor water chemistry were factors that should preclude humpback chub from above Chute Falls. Potential risks of the Chute Falls translocation The translocation effort has potential for establishing a reproductively isolated population of humpback chub above Chute Falls. This holds some potential genetic implications. First, since humpback chub apparently did not formerly reside above Chute Falls, this suggests that gene flow (by natural means) from the main LCR population to the founder population will be zero. Offspring from the translocated fish will have only one direction to go (downstream). Even when numerous individuals are translocated, bottlenecks may occur early in population establishment, leading to reduced genetic diversity (Stockwell et al. 1996). Second, if the effort is not continued, the founder population will consist of < 600 fish (Le., some will not survive the translocations). Since the translocated fish are small (50 to 100 mm), there is no ability to determine sex of the individuals. This means a possibility to transfer unequal sex ratio. In the best-case scenario, if all 600 fish survive 36