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(Tyus 1987). Taba et al. (1965) collected juveniles from backwaters in the Colorado River near Moab, and G.R. Smith (1959) caught two young fish on the Colorado River in Glen Canyon; one from a backwater and one from a creek mouth. In 1950, R.R. Miller seined 6,600 young-of-year along warm, shallow margins of the Colorado River at Cottonwood Landing, Nevada (Sigler and Miller 1963). Marsh and Langhorst (1988) observed that larval razorback suckers in Lake Mohave remained near shore after hatching but either disappeared or migrated to deep water within a few weeks. In recent years, juvenile razorback suckers have been collected from lateral canals off the Colorado River in the Lower Basin (Minckley and Marsh 1989; Charles Minckley, USFWS, pers. comm.). Two were collected in a backwater in the lower Green River (Tom Chart, UDWR, pers. comm.). Observations of young hatchery-produced fish found that they remained along shorelines, in embayments along sandbars, or in tributary mouths, eventually dispersing into channels or larger backwaters (Minckley et al. 1991). Based on limited razorback sucker data and analogy with life history requirements of other native Colorado River fishes, it is probable that young razorback suckers require quiet, warm, shallow water for nursery habitats. These habitats are provided by backwaters and flooded bottomlands that form at various flow levels in riverine environments and by coves in reservoir environments. Backwaters have been identified as important nursery habitat for many species of native fish, providing quiet, warmwater and potential for increased food availability (Valdez and Wick 1983). During high flow periods, flooded bottomlands and tributary mouths also provide quiet water areas and Tyus and Karp (1989, 1990) implied that flooded bottomland may be important for dispersal and rearing of young. Many off-channel habitats were available prior to construction of mainstem dams and channelization (Beland 1953; Tyus and Karp 1989; Osmundson and Kaeding 1991). Wick (1992) concluded that gravel-pit ponds that are adjacent to the river may be a substitute for bottomlands, low lying wetlands, and former oxbow channels. Recently, 97 razorback suckers were collected from waters adjacent to the Colorado River; four from Highline Lake, one from Clough Pond, near Rifle, Colorado, and 92 from a gravel-pit near DeBeque, Colorado (Pfeifer 1993). Providing nursery habitats in backwaters and flooded bottomlands under reduced predator load appears to show some hope for the survival and eventual recovery of this species. Holden and Crist (1981) reported the capture of 56 razorback suckers in the Ashley Creek- Jensen area of the Green River from 1978 to 1980, and about 19 percent of all ripe or tuberculate razorback suckers captured by the Service from 1981 to 1989 were taken in flooded bottomlands and mouths of tributaries. Seasonal movements of some fish into these areas indicates that flooded bottomlands may provide important habitat for razorback suckers. Warmer temperatures and increased food availability offer plausible explanations, and Bulkley and Pimental (1983) reported that adult razorback suckers preferred temperatures of 71 ° to 77°F and avoided temperatures of 46° to 59°F. Tyus and Karp (1990) suggested that both reproduction and recruitment in razorback sucker in the Green River may be adversely 14