Tree ring data of three bottomland hardwood species were compared with reconstructed hydrologic conditions of flooding for the period 1917 through 1978 for a riparian forest along the Kankakee River in northeastern Illinois. Water levels in the forest and streamflow data from the river were matched during a flood in the spring of 1979 to determine flooding duration from available stream discharge data collected in 1917-78. Streamflow was sufficient to flood the forest for at least 10 days during 41 of the 61 years examined; the bottomland was not flooded at all in 11 of the years. Average annual tree ring growth (average ± standard deviation) for the period was 4.52 ± 1.89 mm/yr for Quercus bicolor, 6.77 ± 2.3 mm/yr for Ulmus americana, and 6.26 ± 1.32 mm/yr for Fraxinus pennsylvanica. The species went through similar growth cycles in the 1940's and 1950's. Tree growth variables (radial growth and basal area growth) and flooding and streamflow variables were poorly correlated with significant relationships found only between annual growth of Q. bicolor and U. americana and average annual daily streamflow. A general causal model presents an alternate hypothesis of several environmental factors influencing riparian tree growth in a nonlinear fashion. Forest Sci. 30:499-510.