This paper reviews the traffic volumes and changes in traffic volumes, destinations, and commodity mixes on the Illinois and Missouri Rivers. The time period reviewed is 1972 to 1992. This time period starts before the large increases in grain exports in the mid-1970s and goes through 1992, the last year for which the complete data series was published. Note that 1993 was a year of major floods and barge traffic volumes were atypical in 1993. Data were obtained from the annual publication Waterborne Commerce of the United States. The Illinois River data series includes the Illinois River from its mouth on the Mississippi at Grafton, Illinois to Lockport, Illinois (Figure 1). The Missouri River data series includes the Missouri River from Fort Benton, Montana to its mouth on the Mississippi River (Figure 2). Virtually all of the Missouri River traffic occurs in the lower 735 miles, i.e., below Sioux City, Iowa, with the vast majority of the traffic occurring in the lowest 375 miles, i.e., Kansas City and below.