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Colorado, Utah, New Mexico, Nevada, Arizona, California) could develop their respective water entitlements. The dam and reservoir also produce hydropower and provide fish and wildlife benefits. Mean annual discharge in the Green River upstream of the Yampa River has not changed appreciably as a result of dam closure (59 m3/s post-dam versus 56 m'/s pre-dam). However, seasonal flow variability has been considerably reduced. Since Flaming Gorge Dam was closed in 1962, June mean maximum flow of the Green River has been reduced from 381 m'/s to 139 m'/s (Tyus and Karp 1991, Muth et al. 2000). Flows at all other times of the year have increased. In addition, releases for peaking power production were made up to twice per day, resulting in short-term daily fluctuations much greater than historically occurred. Annual volume of sediment transported by the Green River below Flaming Gorge Dam has decreased by 54% as a result of deposition in the upstream reservoir (Andrews 1986). The relatively unregulated Yampa River, a major tributary of the Green River, exhibited greater seasonal variability and more stable daily flows than the Green River below the dam. During the period 1963 to 2004, annual flow maxima in the Yampa River occasionally reached 566 m'/s, but sometimes declined to < 2 m'/s in late summer (U. S. Geological Survey et seq.; Maybell Gauge, 09251000). METHODS Methods of fish collections used in this study were essentially identical to those reported in Bestgen et al. (2006). Collections ofsmall-bodied (< 150 mm TL, most were 25 to 75-mm TL) and large-bodied (150- mm TL or greater) fishes were made from 2002 to 2006 to describe current distribution and abundance patterns of fishes in the Green River from Swinging Bridge in Browns Park to the downstream end ofIsland-Rainbow Park, portions of which were reported in Bestgen et al. (2006). Water temperature and discharge data were used to understand the relationship of physical factors to longitudinal distribution and abundance patterns of fishes in the regulated portion of the Green River. Discharge and temperature regimes associated with specific dam operations were compared to changes in fish distribution and abundance patterns. 8