Frac sand is currently being mined from sandstone formations in much of western and central Wisconsin. The same formations are less well exposed and generally more fine-grained in the eastern and southern parts of the state
Although Texas and Illinois top the list of U.S. industrial sand producers, thanks to their large processing operations, most of the sand for fracking will come from the Midwest, primarily the red-hot mines of Wisconsin and Minnesota.
It is used in the hydraulic fracturing process (known as “fracking”) to produce petroleum fluids, such as oil, natural gas and natural gas liquids from rock units that lack adequate pore space for these fluids to flow to a well. Most frac sand is a natural material made from high-purity sandstone.