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<br />-' I ~. <br /> <br />( <br /> <br />large, mainstem dams ,on the upper Colorado and its tributaries. The project <br />included six reser~o~rs: Blue Mesa, Crystal, Flaming Gorge, Morrow Point, <br />Navajo, ~nd Powell. The last to be constructed, Lake Powell~ was completed <br />in 1962 ana filled by 1980. <br /> <br />In the early 1960s, the endangered Colorado River fishes were considered <br />undesirable "rough" fish by conservation agencies. As a result, the largest <br />rotenone treatment in the United States was conducted to remove them and <br />other undesired speci~s such as common carp (Cyorinus caroio) from the Green <br />River above Flaming Gorge Dam. The goal was to create a sport fishery, <br />principally for introduced salmonids (Binns 1965; Holden, Chapter 3). This <br />1962 treatment was intended to eliminate native fishes from the reservoir <br />basin and above (Rinne and Turner, Chapter 14). Because the rotenone was not <br />completely detoxified, it continued downstream into Dinosaur National <br />Monument (DNM). Reductions in native fishes were greatest in the uppermost <br />part of the monument, at the Gates of lodore, and diminished as the chemical <br />moved downstream. Although the treatment adversely affected native fishes <br />and invertebrates, ecological changes to riverine environments caused by <br />Flaming Gorge Dam were believed more important in ultimately reducing their <br />populations (Holden, Chapter 3). <br /> <br />Colorado River Storage Project dams and reservoirs, along with private and <br />local water developments, all combined to alter natural flow regimes, water <br />temperatures, and turbidity in much of the upper basin. These projects also <br />resulted in direct losses of stream habitat through inundation by reservoirs <br />and blockage of migration routes. Characteristic high and low water flows <br />