By the 20th century, rural iron furnaces like these had largely become relics of an earlier era as rising transportation costs cut into profits, nearby forests that supplied wood for charcoal had been depleted, and iron production increasingly shifted toward larger, more economical city furnaces tied to the demand for steel. After furnace #2 closed in 1904, workers dismantled abandoned structures, moved some elsewhere, and salvaged wood from others, while vegetation gradually swallowed the two stone stacks that remained. A February 13, 1902 letter published in the Semi Weekly News in Huntingdon, Pennsylvania predicted that the township's charcoal furnace, Greenwood Furnace, would likely cease operations because of the scarcity of accessible timber. In 1936 the Civilian Conservation Corps stabilized stack #2, the ruin on the right, allowing the most striking reminder of the local iron-making legacy to re-emerge, and about forty years later archeologists investigated the ruins of stack #1 on the left.