Exchange of larval fish between a river's main channel and its floodplain backwaters is compromised by sedimentation. Restoration projects to reduce sediment loading are being implemented in large rivers of the midwestern United States to curb backwater habitat loss and restore backwater-to-river connectivity. During 2004 and 2005, drift nets were set bidirectionally (with and against the flow) within a constructed channel between the Illinois River and an adjacent, 1,100-ha restored backwater, Swan Lake, to investigate the interplay between life history strategies and lateral drift on a diel and seasonal basis. Ambient larval density and species composition within the river and backwater also were quantified. Drift was positively correlated with water velocity in the main stem during 2004, and an estimated 32.3 × 106 larvae drifted at the surface of the channel into Swan Lake. In the absence of a flood in 2005, the density and composition of the larval fish assemblage in Swan Lake and the Illinois River appeared to drive larval drift timing, magnitude, and composition. Swan Lake's restoration has maintained some river connectivity and lateral drift functionality for resident fish, but its functionality compared with natural, connected river–backwater systems remains unknown.