This dissertation examines several issues regarding the congestion on the Upper Mississippi River and Illinois Waterway. Chapter II identifies and measures the impact of lock congestion on grain barge rates on these waterways. Results indicate grain barge rates on both rivers are not affected by lagged lock congestion. In present time, however, lock congestion in the lower reaches of the upper Mississippi and Illinois Rivers are found to increase barge rates that link the north central United States to the lower Mississippi Gulf port area. The findings suggest the impact of lock congestion on grain barge rates is moderate. Chapter III explores the interaction between grain prices in export and domestic markets and transportation rates linking these markets over time. Three model frameworks were evaluated and some consistent results are observed. In general, shocks in transportation rates (barge, rail, and ocean) explain a great proportion of the variation in corn and soybean market prices in the long run, suggesting the importance of transportation in grain price determination. The volatile ocean freight rates are the mostimportant transportation rates contributing to the variation in grain prices, while shocks in barge rates on the Upper Mississippi River and Illinois Waterway generally explain less than 15 percent of the variation in grain prices. The dynamic interrelationships among the six evaluated transportation rates are also found. In addition, the north central corn markets likely have the most influence over other markets while soybean export price dominates the soybean market in the long run. Chapter IV estimates the structural demand for grain barge transportation on both the upper Mississippi and Illinois Rivers. Results suggest foreign grain demand is the most influential force affecting grain barge demand on both rivers. Also, results indicate an inelastic demand for grain barge transportation on the Upper Mississippi in the short run; demand is price elastic in the long run. The price elasticity for grain barge demand on the Illinois River is consistently inelastic. Additionally, the winter season and floods affect demand on the Upper Mississippi negatively, while barge demand increases on the Illinois River in winter.