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4 are shallower, less turbid, and are not diluted by the colder upstream waters. , . . , -, Adult Colorado squawfish utilize a wide range of habitats depending upon the time of year. They reside primarily in pools and slow runs (low velocity areas) in the winter before they migrate to spawning areas. In the spring, they are found primarily in backwaters, connected gravel pits, and slow runs. In the summer they prefer fast and slow runs, which are rich in food items and contain gravel bars which are necessary for spawning (Osmundson et al., 1995). Many of these habitats are found in areas of multi-thread channel. Areas of multi-thread channel allow efficient exploitation of a range of habitats for daily requirements of forage, rest, and predator avoidance, while conserving travel energy for reproduction and growth (Osmundson et al., 1995). Perhaps more importantly, areas with multi-thread channels provide backwaters in close proximity to spawning bars, which minimizes the downstream distance that larvae drift. This can be critical since larvae must reach suitable feeding areas before their yolk supplies are depleted (Tyus and Haines, 1991). For these reasons, areas of multi-thread channel are believed to be essential to the survival of the species. Osmundson and Kaeding (1991) tested whether adult Colorado squaw fish show a preference for complex channel reaches. They partitioned segments of the Colorado River near Grand Junction, Colorado into areas of either simple (one channel with no major backwaters or islands) or complex channel (multiple channels or single channel with a large backwater), and tracked adult Colorado squawfish throughout this reach between 1986 and 1989. The results of a binomial X2 test, based on 428 fish locations, showed that the fish were located in ...] .;-: :-,. .J -}... .J 'j 1 J ] I ] j _ J ] 1 .J