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Yampa River hydrograph should be protected as one effort toward recovery of the rare indigenous fishes. We recommend that the Yampa River be given highest priority for water rights acquisition in the upper Colorado River basin. Further efforts to coordinate Green River flows (by operation of Flaming Gorge Dam) with timing of Yampa River flows are needed for recovery of the rare Colorado River fishes in the Green River basin. The following summaries highlight the flow events we consider to be important toward recovery of the rare Colorado River fishes in the Green River basin. These are presented by species and time of year. Colorado Squawfish Spring Migration signals the onset of the reproductive cycle in Colorado squawfish, and we consider migration cues (e.g., high spring flows, increasing river temperatures, possible chemical inputs from flooded land) important to maintain successful reproduction. Duration and timing of spring runoff must be further evaluated with these needs in mind. Migration routes must be protected and barriers discouraged. Summer Spawning and egg deposition occur in association with declining flows, decreasing sediment transport, and increasing temperatures. Relations between these and other variables (e.g., type of water year) and spawning should be further evaluated with respect to low-, average-, and high-water years. The gradual decline of summer flows following spring scouring maintains natural sediment transport equilibria, prevents siltation of spawning substrate, aids downstream drift of larvae, and creates productive nursery areas. Fall Flows maximizing backwater habitat (quantity and quality) in the upper Green River should be determined using both the Yampa and Green rivers. Unusually high flows in late summer and fall reduce availability of nursery habitat for young Colorado squawfish. Winter Stable flows reduce ice scouring of shoreline habitats that are used by overwintering adults and young. In the event that flow quantifications through ice cover are not feasible, an alternative is to provide best conditions observed during the 198fr88 winter habitat study (Wick and Hawkins 1989) or subsequent studies. Humpback Chub Spring Spawning of humpback chubs occurs shortly after highest spring discharge. Relations between these events should be further evaluated with consideration of availability of shoreline eddy habitat. The relation between spring flows and abundance of channel catfish should be evaluated. Summer-winter Habitat use and flow needs of the humpback chub during late summer and winter are not well understood, but minimum flows necessary for maintenance of riverine, canyon-bound habitat should be determined for dry, average, and wet years. Conditions favoring reproduction and growth of channel catfish should be identified and avoided because of possible negative interactions of these species. Bonytail Chub Studies are in progress to evaluate habitat use and needs of this species. Results of reintroduction efforts should be evaluated with respect to the current Yampa River hydrograph. Razorback Sucker Spring Spawning of the razorback sucker occurs with increasing flows associated with highest spring runoff. Curtailment of spring runoff in the mainstream Green River may be associated with loss of recruitment to the juvenile stage. Relations between these events should be further evaluated with consideration of larval distribution, habitat use, and abundance in the Green River. Flooding of bottom-land during spring runoff may be beneficial to adults and important for dispersal and rearing of young. Influence of Yampa River flows on razorback sucker spawn in the Green River should be more fully evaluated. Summer--winter Little is known of habitat needs of the razorback sucker during this period. Thus, low, stable flows (natural condition) should be maintained until additional information is available. 23