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RESULTS Overview.-Study results are reported in several closely related sections. First, we describe the major changes in physical habitat imposed by construction and operation of Flaming Gorge Dam. Second, we compaze the composition and reproductive status of the fish community of the regulated reach since before construction of Flaming Gorge Dam in 1962 until 1996. Third, abundance patterns of fishes sampled at two sites in Lodore Canyon are compared between the periods 1978-1980 (Holden and Crist 1981) and 1994-1996 (this study). Fourth, we analyze longitudinal patterns of distribution and abundance both for fish captured with seines and for those captured with electrofishing gear. Fifth, species composition and abundance patterns of drifting larval fish in the Green River are compared to patterns observed in the unregulated Yampa River. Sixth, we detail species distribution and abundance patterns in accounts of rare native species and selected non-native piscivores in the study area. In the seventh and last section of this report, we present empirical regression models to predict water temperatures of the Green River downstream of Flaming Gorge Dam. Conclusions emphasize management actions needed to restore habitat and fish communities in the Green River upstream of the Yampa River. Effects of Flaming Gorge Dam on Green River discharge and temperature patterns.-Prior to construction of Flaming Gorge Dam, discharge patterns of the Green River exhibited high spring peaks followed by lower, more stable base flows in other seasons, particularly winter (Fig. 2). Water temperature ranged from a low of 0°C in winter to over 22°C in summer (Fig. 3) and water was sometimes turbid from fine silt loads. At least three major dam-related events potentially affected physical habitat and the fish community of the upper Green River: dam closure in 1962, penstock modification in 1978, and flow re-regulation in 1992. Effects of construction and dam operation on fishes were summarized in two major research efforts, the first from 1963-1966 (Vanicek and Kramer 1969, Vanicek et al. 1970) and the second from 1968 to 1971 (Holden and Stalnaker 1975a and 1975b). Riverine habitat in the reservoir zone was eliminated by inundation; naturally variable and spring discharge maxima 12