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17 I I I I I I I I I I I I I I I I I I I Local movement by Green River fish was characterized by rates of 15 to 23 m/hr, as normal for overwintering adult Colorado squawfish, in the absence of fluctuating flows and ice. Average local movement by five fish under stable ice was 29 m/hr. Although not significantly different from movement in the absence of ice, greater movement under ice-- particularly in shallow water--indicates use of ice as cover. Yampa River fish were also observed in relatively shallow water in the presence of surface ice. Razorback Suckers Net long-range movement by radiotagged adult razorback suckers in the Green River averaged 3.4 kIn (n=8, range of 0.0-16.9 kIn) and 4.7 kIn (n=9, range of 0.8-11.7 kIn) in Winter 1 and Winter 2, respectively. Over 75 percent (13) of 17 fish monitored remained within 5 kIn of their origination location. Valdez and Masslich (1989) concluded that, like adult Colorado squawfish, adult razorback suckers in the Green River probably overwinter within reaches 2 to 5 kIn long. Adult razorback suckers also showed a fidelity for specific overwinter locations. One razorback sucker, radiotagged and monitored in Rainbow Park (RM 327-328) on October 28, 1986, was recaptured at a suspected spawning area (Razorback Bar,RM 311), about 25 kIn downstream in April, 1987 (Personal Communication, Harold Tyus, U.S. Fish and Wildlife Service, November 1987). The fish was relocated, via radiotelemetry, in the same eddy complex (RM 327.3) over 13 months later on December 4, 1987, and monitored near this site until the radiotransmitter failed on March 24, 1988. This fish apparently traversed Split Mountain Canyon to and from the spawning area. A different adult razorback sucker was radiotagged near Mitton Park (RM 344.1) on October 27, 1986, and relocated nearly