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6 of 56; 2004, 9 of 20; 2005, 24/95; 2006, 25/78). The proportion was high in 2004 because we chose to sample relatively more isolated pools, places where native fishes tended to reside, and obtained relatively few samples in other habitat types. Patterns of native fish abundance in the Yampa River were also supported by logistic regression analysis and showed essentially the same patterns as those for native fish presence. The proportion of native fish in a sample was significantly higher if it was from an isolated pool habitat but lower if it was from main channel habitat (Table 8, Chi-syua,-e = 197.2, p < 0.0001); the large chi-square value indicates again that this was, by far, the largest effect. Proportion of native fish in the sample was higher if smallmouth bass were absent in the sample (Chi-square = 18.4, p < 0.0001) but decreased as number of smallmouth bass in the sample increased (Chi- square = 3.9, p < 0.049). Solving the equation in the table, assuming that the sample was from an isolated pool with no smallmouth bass, predicted that the proportion of native fish in the sample (as a %) should be 15%. Note that the 15% value matches up well with previous descriptive data reported for isolated pools (e.g., 16.7% native fish in isolated pools where bass abundance was very low). Solving the equation in the table, assuming that the sample was from the main channel and bass were present (n = 1), predicted that the proportion of native fish in the sample (as a %) should be < 0.1 %. The proportion of native fish in a sample was not affected by whether the sample was from a control or treatment reach (Chi square value = 0.31; p = 0.58). Again, one would expect the proportion of native fish in samples collected in the treatment reach to be higher than in the control reach if treatment reach predator removal was having a significant and positive effect on survival of native fishes. Most smallmouth bass and native fishes captured in isolated pools were age-0 fish, based on their size at capture. Higher relative abundance of native fishes in isolated pools could be a function of timing of reproduction relative to high flows. Areas that eventually become isolated pools may be available to fish in the main channel mostly during higher flow events relatively early in the summer, but are cut off only after native fishes invade these areas and are subsequently isolated. Perhaps the majority of smallmouth bass do not spawn in time to access areas that eventually become isolated pools, and thus, are relatively rare. It may also be that 17