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fluctuated widely throughout the year, they do so in a predictable, cyclic manner. Evolution has allowed the native species of fish there to adapt to and flourish under such fluctuating conditions. Unfortunately, the suc- cessful specialization for life in the.unique environment of the Colorado River has left some species ill-equipped to live or reproduce under the new conditions. Changes in the system have proceeded too rapidly for evolution to allow the species to adjust. However, as manipulation of flow and temperature regimes have acted negatively on the native fish and allowed introduced species to flourish, so too might new, carefully planned manipulations of flow be used to benefit the natives and perhaps aid in controlling the populations of introduced ones. The U.S. Fish and Wildlife Service (USFWS) is responsible for developing year-round flow recommendations for the aforementioned 15-mile reach of the Colorado River upstream of the confluence of the Gunnison River. Kaeding and Osmundson (1989) recently provided provisional flow recommen- dations for the months of July, August and September. We now continue with this process and here present recommendations for flows during the remain- der of the year (October-June). Methodologies used to arrive at recommen- dations for these months differed from those used previously for the summer months. The reasoning behind our selection of the methods used is outlined in the section entitled 'Rationale for Methodologies' included as Appendix I. The primary difference is the reliance on empirical data for the spring and winter recommendations rather than on the analytical model used in the development of summer flow recommendations. USFWS is currently developing a new method for relating flow-levels to availability of var- ious important habitat types. Recommendations provided in this report and 3