I ncreased ethanol production in Iowa and other Corn Belt states has led some to believe that the Midwest will no longer need to export any of its corn to other states or other countries. Farmer-advocates of more ethanol see such a future as making them free from reliance on unpredictable export markets, free from reliance on aging Mississippi River locks and dams, and free from worrying about the impacts of trade agreements and foreign competition. But such a future would not make the Corn Belt free of the need to export distillers grains, an ethanol by-product.