INDIANAPOLIS (AP): The harsh 2014 winter has drained road salt supplies and driven up prices across Indiana.

Indiana Department of Transportation spokesman Will Wingfield says salt prices on regional bids across the state rose an average of 57 percent from last year. The department used more than 437,000 tons of salt last winter.

The agency already has 142,000 tons of salt on hand this year, and Wingfield says more is on order so the state is ready for this winter's start.

Highway officials and companies blame the price increases on supply and demand as states race to replenish stockpiles of salt that dwindled last winter.

Salt supplier Cargill says its inventories are also running low. It's even shipping in salt from South America to meet the demand.