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. Basin are below freezing from November to March, all water bodies freeze for a relatively long period. The longer the area remains below freezing, the greater the depth of ice in these flood plain wetlands. Depth of ice over the Stirrup flood plain wetland was about 0.28 meters in both 2006 and 2007 (deepest point in the Stirrup was 0.76 m in 2006 and 1.2 m in 2007), suggesting that shallow flood plains (e.g., Thunder Ranch) may freeze to the bottom. Single breach wetlands entrain less water and fewer particles, but several (Stirrup, L- 7) are deep enough to successfully overwinter fish. This suggests that certain trade-offs or combinations of strategies may be necessary to achieve recovery of razorback sucker through use of flood plain wetlands with different breach configurations. Stewart Lake may offer both relatively high entrainment rates (when it is a flow-through site) and may be deep enough to overwinter fish. Unfortunately, Stewart Lake suffers from contaminant issues (e.g., high levels of selenium) that may limit its utility as a place for razorback sucker recruitment. The USFWS Ecological Services Office, in Salt Lake City, Utah is currently in the process of testing Stewart Lake for selenium concentrations and UDWR and the U.S. Bureau of Reclamation are in the process ofremediating the wetland by filling and draining the area multiple times during the year (Miles Hanberg, UDWR; Nathan Darnall, USFWS, personal communication). When this process is complete, selenium levels should be reduced (limitations of selenium levels for razorback suckers is equivocal) and thus Stewart Lake may contribute to recovery efforts for razorback sucker in five to 10 years. While few are in agreement as to the effects of large amounts of selenium in larval razorback suckers, managers will need to consider all of these factors when formulating an optimal flood plain management strategy in the middle Green River. . . . . . . . . . 53 .