This paper examines the impact of biofuel expansion on grain utilization and distribution at the state and cropping district level as most of grain producers and handlers are directly influenced by the local changes. We conducted a survey to understand the utilization and flows of corn, ethanol and its co-products, such as dried distillers grains (DDG) in Iowa. Results suggest that the rapidly expanding ethanol industry has a significant impact on corn utilization in Iowa. Comparing to the earlier survey results, ethanol plants drew a considerable amount of corn away from traditional destination markets, such as feeders or export markets. A major portion of corn supplies came from in-state sources, while the sales of Iowa ethanol and DDG were dominated by out-of-state buyers.