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a white sucker and hybrids declined in a downstream direction in Lodore Canyon, presumably in response to warmer water temperatures. Possible occurrence of Utah sucker is being investigated with comparisons of museum specimens. Trammel net sampling in Whirlpool Canyon detected a small population of humpback chub and a relatively large population of roundtail chub. Hatchery-stocked bonytail were also captured. Drift net sampling failed to detect reproduction by Colorado pikeminnow. Drift net sampling revealed that fish, including early life stages of smallmouth bass, were displaced in response to turbidity and higher flow events. Colorado pikeminnow continued to use Lodore Canyon heavily in summer, based on captures we made and those in a concurrent companion study. Ripe male Colorado pikeminnow were detected there in 2001 and 2003, indicating suitable conditions for reproduction and perhaps, attempted spawning. Based on our 2002 to 2004 sampling, the net effect of flow and temperature regimes on the native fish community, was mixed. During this study, we were able to obtain reliable information on the response of the fish community to flow and temperature effects, but only at the lower end of the flow spectrum and the high end of the temperature spectrum. Flow and temperature conditions observed in 2002 to 2004 fell within the bounds for recommendations that would be implemented in years with low or moderately low water availability, which happen in only 30% of flow years. Average, moderately high, and high flow years, which occur the other 70% of the time, were not evaluated because those conditions were not realized during this study period. Additional years of sampling when those flow conditions are available are needed to fully assess the effects of pending flow and temperature recommendations for Flaming Gorge Dam on the fish community of the Green River. vii