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. higher flow years (when river-flood plain connections are achieved) are unknown. However, if, during higher flow years, razorback sucker larvae from Razorback Bar are carried up to nine kilometers further downstream, they would likely be available for entrainment into Stewart Lake. In addition to marked larvae, wild larvae were also captured at the 8 km sampling site adjacent to the Thunder Ranch flood plain, predominantly on river left (Figure 9). The large number of wild razorback sucker larvae captured during this study was surprising, especially given the relatively short sampling time at each site. The number captured in a few hr of drift net sampling was equivalent to the number captured in entire seasons of light trapping in backwaters in the middle Green River area in some years (Bestgen et al. annual reports, project 22f). If one assumes that our near-shore only samples were representative for razorback sucker larvae density across the entire channel, and that we sampled about 0.12% of the flow at the 8 km site, from the 188 unmarked larvae that we captured, we estimated that about 156,600 ([100%/0.12%]*188) razorback sucker larvae were transported downriver in that five-hr sampling period. Given that few wild adult razorback suckers were likely remaining in the middle Green River in 2004 (Bestgen et al. 2002), capture of many unmarked larvae presents unequivocal evidence that hatchery-produced and stocked adults are successfully spawning. Spatial distribution of marked and wild larvae, and spatial distribution of beads released at Razorback Bar suggested that there was an additional spawning area downstream from Razorback Bar and located on river left, but the exact location was not known. This uncertainty was resolved in 2005 when ripe and presumably spawning adults were located at Escalante Bar, which is just upstream of the Thunder Ranch wetland complex on river left. This location is outside of Dinosaur National Monument and thus has a high probability for seeing human impacts in the future. Northeastern Utah is also an area of high natural gas and oil exploration . . . . . . . . . 35 .