One market report predicts the value of proppant sand will top four-billion dollars this year and approach six-billion over the next five years. One of the best sources for the sand used by domestic oil exploration efforts is in western Wisconsin. About one-third of the U-S supply of industrial sand comes from this state. The U-S Energy Information Agency is estimating domestic crude oil production will reach record levels the rest of this year and into 2019. So-called “northern white sand” is used to keep open cracks in rock formations deep underground while the oil is being extracted.