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. DRAFT . near the Jensen Bridge at RM 301.3 (Figure 6), and two in the lower region near the Bonanza Bridge at RM 289.8 (Figure 7). No main channel ice was present during the observations of these four fish, and 50 their behavior is not related or influenced by ice conditions. . The fish in the upper region and the two fish in the lower region were observed for 24 hours. Movement behavior by these fish revealed three aspects common to most of the squawfish observed during winter conditions; (1) local movement over a 24-hour period was generally within a 50 m diameter area, (2) movement was almost always within a defined habitat with greater than average river depth and lower than average velocity, and (3) the majority of time was spent in two to five "favorite spots". These favorite spots often exhibted very similar depth, velocity, and substrate characteristics. . At least some of the local movement by squawfish GR6118 (Figure 5) appeared to be in response to a decrease of 12 inches in river level. During a period of about 21 hours, the fish occupied four favorite spots, but returned to its original location when the river flow resumed to its original level. Thus, gross movement by this fish was 80 m but net movement was O. . In the case of squawfish OR4021 (Figure 7), four favorite spots were occupied during a 24-hour period for a gross movement of 50 m and a net movement of 10 m. This fish was located near Bonanza Bridge, about 120 miles downstream of Flaming Gorge Dam, and such a distance that fluctuating releases were ameliorated to vertical changes in water level of only 2-3 inches. Some movement by this fish may be attributed to changing water levels, but most was probably due to normal repositioning. A second squawfish, GR6106, in the same vicinity, visited five favorite spots, all within a 50-m diameter area and all within a slackwater habitat. Gross movement by this fish was 118 m while net movement was 10 m. Some movement by this fish may be attributed to changing water levels, but most probably reflects normal behavior. It is noted that all three squawfish returned to either their original position or within 10 m thereof in the 24 hour observation period, which reflects a flow cycle from the dam. This suggests that even subtle vertical changes in water level can lead to movement by the fish. . . . Observations of squawfish GR6120 (Figure 6) are presented to illustrate movement by a fish that is directly attributed to decreasing water levels. During a 3.5-hour period, this fish occupied nine spots in a line from shallow to deep water in a trough along a submerged sand ridge. This fish, as well as most of the radiotagged squawfish observed, appeared to change position in the channel to spots that satisfied certain minimum depth criteria of about 3 feet with 0.6 velocities of less than 1 fps. The movement of this fish in contrast to the three previous fish indicates that extensive local movement depends how well a favorite spot maintains the appropriate combination of habitat parameters during changes in flow level. . 6.1.4.1.2 Razorback Sucker . Four razorback suckers were also selected to depict local movement over randomly-selected 24-hour periods; three in the upper region near Echo Park at RM 344.2 (Figure 8), one in the middle region above Razor Island at RM 312.4 30 .