1. HYDRAULIC FRACTURING
Rail arteries make or break frac sand growth in Midwest
Mountains of smooth, yellowish sand have built up around rail terminals in the Midwest, en route to U.S. shale oil and gas plays. The chalky "frac sand" keeps crude flowing smoothly during hydraulic fracturing, making it one of the most sought-after commodities in Wisconsin and Minnesota. The budding frac sand industry's future hinges on the survival of the U.S. shale oil and gas boom. But frac sand's fate is also tied down to the web of freight railroads that criss-cross the Midwest.