European settlers deforested the land to create farmland. This exposed the soil to intense freeze-thaw cycles, which caused buried stones to "heave" to the surface, creating what farmers called a "second crop" of rocks.
Most walls were built between 1775 and 1825, often called the "frenzy" of wall building, reflecting a period of intense agriculture. Cultural and Environmental Significance Stone Walls
Farmers stacked these endless stones, acting on a "waste-mapping" process, turning a hindrance into property markers, sheep barriers, and a way to utilize the excessive stone. European settlers deforested the land to create farmland
The prevalence of stone walls resulted from a unique combination of natural and human processes: acting on a "waste-mapping" process