This paper attempts to estimate structural demand for grain barge transportation on the upper Mississippi River. Results suggest an inelastic demand for grain barge transportation on the upper Mississippi in the short run while the price elasticity increases to 1.0 in the longer run. Additionally, foreign grain demand and domestic grain consumption are found to influence grain barge demand. Also, the winter season and floods affect demand negatively. Hausman’s specifi cation test shows the ordinary least square and two-stage least square estimates are statistically invariant.