estern Kentucky and Tennessee was once a major iron producer, and the "Between The Rivers" region was its center. Northern industrialists recognized the region's potential when they found iron ore, limestone, and timber -- the three primary ingredients in the smelting process -- plentiful in the area and easily mined. The Cumberland and Tennessee Rivers nearby also provided easy access to outside markets.

Iron production reached its heyday in the mid-1800s. Stewart County alone, in the southern portion of LBL, had 14 operating iron furnaces. These were massive stone and wooden structures which, fed by charcoal made from local timber, produced enough "blast" to fuel the smelting process. By 1830, the region was the third-largest producer of iron ore in the country.

Iron production stalled during the Civil War. The iron factories sat squarely in the path of Northern armies and were a logical target for destruction. Although production resumed after the war, it never returned to its former prominence. By the 1880s, the area's natural resources had been depleted and new production methods moved the industry elsewhere. The area's last furnace ceased production in 1927.

Remnants of this past can be seen throughout LBL. You can study the ruins of two iron furnaces at LBL: Center Furnace, located near the Nature Station, and the Great Western Furnace, near The Homeplace.

Other clues remain: take a stroll along any trail near the Nature Station -- especially the Center Furnace, Long Creek and Honker Lake trails. Look carefully and you'll easily spot numerous smooth, turquoise and deep blue rocks littering the forest floor. This is slag, a by-product of the iron smelting process, and debris from the Center Furnace production of more than 120 years ago.