WHITEHALL, Wis. — A company that was once one of Wisconsin’s biggest producers of frack sand is liquidating one of four state mines.

Hi-Crush Proppants in Whitehall opened in 2014 and had a production capacity of 3 million tons of frack sand per year. Demand for Wisconsin’s northern white sand was high because of its uniformity and strength. The sand is used in hydraulic fracturing for oil and natural gas.

But in recent years, oil companies started using cheaper sand found closer to oil wells, saving as much as $60 per ton by ending shipments from Wisconsin.

Heritage Global Partners has started accepting bids for Hi-Crush’s Whitehall sand production facility. It’s essentially a liquidation sale of the operation or individual pieces of equipment. Hi-Crash declared bankruptcy last year.

The market shift in recent years has been tough for Wisconsin sand mines. In 2019, Superior Silica Sands, declared bankruptcy and shut down mines in Chippewa and Barron counties.

That was followed by bankruptcy filings from Covia Holdings Corp., which operates a mine in Menomonie, and Hi-Crush.