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16 I I I I I I I I I I I I I I I I I I I Average net movement of Yampa River fish in fall, 1987 (September through November) was 1.4 kIn (n=8, range of 0.0-7.1 kIn), while net movement in spring (March-April, 1988) was much greater, with an average of 10.5 kIn (n=10, range of 0.0-69.5 kIn). Valdez and Masslich (1989) concluded that the majority of adult Colorado squawfish in the Green River probably overwinter within reaches 3 to 5 kIn long. Wick and Hawkins (1989) reported that during ice-covered periods, total range of movement of all radiotagged Colorado squawfish was only 0.5 kIn, with individual fish showing seasonal, as well as annual, fidelity to specific fall and winter sites by returning to the same area two consecutive years. Although radiotagged fish remained in specific areas in winter, they were quite active within those areas in both rivers. This local movement in the Green River was often restricted to a specific habitat (e.g., eddy, backwater, run, etc.), in which an individual fish occupied one to several favorite locations for varying periods of time. One Green River fish monitored for 24 hours occupied four different locations within the same slackwater (#OR- 4021). Although the fish moved over 50 m during monitoring, net displacement from the original location was only 10 m (Figure 12). The fish occupied the four locations five times for periods of about 2, 1, 4, 8, and 9 hours. A second Green River fish (#OR-6101), monitored fo~ 24 hours, moved a total of 118 m, with net movement of ()nly 10 m. Similarly, the Yampa River fish moved between several favorite spots within a habitat ( e.g., embayment, backwater, etc.), staying in a spot. for several minutes to several hours before moving. Like the Green River fish, the Yampa River fish repeated this pattern of movement, often occupying the same spot more than once.