The production capacity of corn ethanol as a transportation fuel is experiencing rapid growth in the United States. The demand is driven by increased prices of gasoline, government mandates, incentives, desire for cleaner fuels, and the need to be more self-reliant in energy sources. Continued strong growth of the corn ethanol industry will depend on profitability by both suppliers and producers. This in turn will be influenced by several factors such as demand, government incentives, feedstock availability and prices, processing plant capacity, and efficient farm and ethanol processing technologies. How and to what extent will the projected growth of the corn ethanol industry in the United States be influenced by some or all of these factors? We use system dynamics modeling to construct a causal-loop structure of the corn ethanol industry and stock and flow diagrams to explore how possible changes in projected factors and growth indicators will affect the industry. Currently, planners and researchers explore various energy supply options by the year 2030. Using system dynamics modeling, this paper explores different possible growth scenarios of the industry for the next twenty years.