Sand is the crucial ingredient in the oil and natural gas extraction process known as fracking, and there are large deposits of it in the steep bluffs along the Mississippi River.
But demand for sand has dropped. This 150-foot-tall hill in Saratoga township is estimated to hold about 1 million tons of silica sand used for mining.
The 19-acre site is the only mine approved in the region since the debate over silica sand mining began a few years ago.
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