A sand mining company argued before the state Supreme Court on Wednesday that it should be allowed to mine silica sand in Winona County despite a local ban on the practice.

Attorneys for Minnesota Sands have argued that Winona’s 2016 ban, the state’s first, violates the Commerce Clause of the U.S. Constitution and violates the company’s property rights to extract minerals. The county ban focuses on silica sand, sometimes called frac sand, which is valued by the fossil fuel industry for its strength and uniform shape, qualities that make it useful for the extraction of natural gas, oil and other natural gas liquids through fracking.

The company’s arguments were rejected at the district court and appeals court levels, with appeals court justices issuing a 2-1 split decision last year in favor of the county.

Wednesday’s hearing, held at the University of Minnesota Law School, lasted about an hour. The justices typically release an opinion three to five months after hearing arguments, according to the court’s website.