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Fish Movement Colorado squawfish moved throughout the study both locally and for longer distances in the river. One fish moved approximately 7 miles upstream and then moved downstream 6 '/z miles by the end of the study. This particular fish moved upstream during a time when flows were lowest in the summer and moved back downstream at higher flow rates. The upstream movement occurred through numerous shallow riffles and either through or around the Patrick Sweeney Diversion structure. Other fish moved only slightly and stayed within the same river mile, however, on most 24 hour observations there was a local movement shown of several hundred feet by the fish that were being observed with peak movement occurring after dusk. The activity increased after dark with fish moving either upstream or downstream to a probable feeding location and then returned to the original observation point. Channel catfish and northern pike showed less movement during the study. Most of these fish remained in the same river mile where they were originally captured with the exception of two channel catfish that moved downstream approximately 4 miles at the late October observation period. One of those was observed on the ground by ground crews; the other was observed only from air and that contact was not verified on the ground. During one 24 hour observation of northern pike, that fish exhibited the same local movement as Colorado squawfish. Activity increased after dusk. The fish moved upstream several hundred feet. That movement peaked just before midnight and the fish returned back to its original location before dawn the next day. Habitat Use Colorado squawfish almost exclusively used pools throughout the observation period from July through October (Figure 36). Two of the five fish implanted did use run Draft Yampa River Radio Telemetry Report Miller Ecological Consultants, Inc. Page 50 December 13, 1996