A man-made clearing is a tract of land from which trees, roots, and stones have been removed, making it suitable for settlement and farming, while the surrounding forest is left intact. Such creation of open space has played a signiﬁcant role in the environmental history of the North American continent. Early European colonists, encountering vast forests of hardwoods, ﬁrs, and white pines, began the backbreaking work of making the land suitable for plowing, as romanticized by James Fenimore Cooper in The Last of the Mohicans: “The trees of many acres had been felled, and the glow of a mild summer’s evening had fallen on the clearing, in beautiful contrast to the gray light of the forest.” White pines became ship masts, and stones were piled into boundary walls. In a few hundred years, as the country’s agricultural center moved west, these clearings extended hundreds of miles to Illinois and eastern Missouri. The farmlands of Iowa, once protected by a mosaic of gallery forests, prairie vegetation, and wetlands, are now subject to erosion. But the northeastern forests are recovering. Today, a hiker in the New England woods will ﬁnd mossy remnants of stone walls surrounded by birch trees and other hardwoods, signs of the old forest’s return.