Some of the best frac sand to be found–the finest particles–come from Wisconsin sand mines. Once upon a time Wisconsin was the primary frac sand producing state, for both the northeast and the southwest. But then Texas oil frackers began experimenting with Texas sand and found they could use it. No, the Texas sand is not quite as fine (or good) as Wisconsin sand, but it works. And it’s cheap, because transportation costs are low. Shipping sand from Wisconsin to Texas by rail costs big bucks. The northeast is not blessed with its own sand mines for fracking, so we still depend on places like Wisconsin. And now, increasingly, Wisconsin depends on us.