Limestone
LTV Steel owns a 53.5% interest in Presque Isle Corporation of Alpena, Michigan, which operates a limestone quarry in Stoneport, Michigan, on Lake Huron. It is one of the top five producers in North America, serving the midwestern metallurgical and construction markets.

Burnt Lime
LTV Steel operates a burnt lime plant at Grand River, Ohio, which processes limestone from Presque Isle and other sources into a variety of burnt lime products. In addition to its captive market, Grand River also serves the expanding steel desulfurization market, as well as water treatment, agricultural, sewage treatment and land stabilization markets.