The inland navigation simulation model is part of the methods and models developed by the Office of the Chief of Engineers to assist the US Army Corps of Engineers in efficiently and effectively managing the inland waterway system. The model is used to evaluate system performance under current or proposed conditions. Verification and evaluation were critical tasks in establishing a basis for confidence in the model results. The testing effort focused on four areas:(a) determination of steady-state conditions,(b) minimization of the effects of randomness,(c) sensitivity analysis of key input parameters, and (d) historical comparison. Three versions of the model were tested. Each subsequent version incorporated more explicit representation of various navigation lockage activities and corrected deficiencies found in earlier versions. The preliminary findings of the Corps of Engineers evaluation study indicate that the model performs satisfactorily navigation studies will depend heavily on the quality of data, the input specifications, and the computer and human resources assigned to the task./Author/