There is a deposit of limonite (Iron Ore) about 3 miles northeast of Waukon called Iron Hill, holding an estimated 10 million tons of ore. This is the highest point in northeastern Iowa. the Waukon Iron Company began developing an open-pit mine and ore-washing plant on this site in 1899, with a capacity of 300 tons per 10-hour shift. Production was seriously limited by the need to haul the ore 3 miles to the railroad, and the mine was, ultimately, a failure.