Grist: When most people think about Wisconsin, cheese, breweries, and cornfields spring to mind. But the fracking industry is interested in something else the Badger State has to offer: sand. A sand-mining boom has gotten rolling in Wisconsin over the last three years. The states quartz-based sand is strong and spherical, nicely suited for injecting underground with water and chemicals to prop open cracks in fractured shale, allowing natural gas and oil to be fracked. The spoils of Wisconsins $1 billion...