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recorder. It allowed us to observe diurnal, nocturnal, and crepuscular patterns, swimming speeds, and activity levels of fish. Twenty-six hours of video showed 1,973 fish, of which one or two were suspect Colorado pikeminnow. With more experience, investigators can learn to identify the fish with more certainty. This study was unable to show whether or not typical winter flow operations at Flaming Gorge Dam to meet hydropower needs influenced overwinter survival of young Colorado pikeminnow. Several investigators have hypothesized that winter operations of Flaming Gorge Dam reduce age-0 fish survival because fluctuating discharge and associated changes in water surface elevation modify the characteristics of nursery habitats which causes an increase in fish activity (Carlson and Muth 1989; U. S. Fish and Wildlife Service 1992; Valdez et al. 1999; Haines et al. 1999). A 24-hour hydropower release from Flaming Gorge Dam during this study usually fluctuated about 600 to 800 cfs, producing stage changes at the Jensen gage of <0.1 m (93 miles downstream of Flaming Gorge) and about <0.01 m at the Ouray bridge. These stage changes had only minimal affect on backwater habitats and were limited to the upper end of the nursery area. These flow fluctuations did not alter physical morphology of backwaters studied in the Ouray Backwater Complex. However, the formation of ice jams, as observed in the 1999-2000 winter, had far greater affect on backwater nursery areas, increasing stage by 0.75- 1.50 m, and resulting in the transformation of many backwater habitats into flow-through areas. The role of fluctuating winter flows from Flaming Gorge Dam in the creation of ice jams is unclear to us. Some investigators have speculated that fluctuating winter flows may dismantle ice cover which acts an insulator, allow the creation of frazil ice, and may result in ice jams. However, a more recent study found that fluctuating winter flows from Flaming Gorge Dam A-x