The drought in the Midwest is one for the record books. In addition to taking a toll on crops, livestock and municipal water supplies, it is constraining freight traffic on inland waterways. The Mississippi River, a major thoroughfare for grain, coal, petroleum, crushed rock and other commodities, is 17 feet lower today than it was two months ago. The low river state is costing barge owners and tow operators money because they have to light load, Mark Mestem...