he bedrock is limestone. Although typically buried beneath soil and vegetation, where limestone can be found—in freshly tilled fields, commercial quarries, highway road cuts, and in sporadic outcrops along hills and in stream valleys—the rock feels slightly gritty and ranges in color from medium gray to blue to tan, representing the vagaries of its marine depositional environment and deep time. The limestone has weathered in the humid climate of central Pennsylvania to a rich, reddish soil that is notably fertile; farmers say the soil is sweet. The valley is enclosed by linear ridges of convoluted sandstone, shale, and quartzite strata that hold only thin soils. The valley is filled with farms and towns. The ridges are forested.
In 1764, when the first European, James Potter, stood on the surrounding ridges he proclaimed: “By heavens...I have discovered an Empire!” What vista did he see below to justify this exclamation? A vast expanse of abundantly-watered gently rolling land with sweet soil covered in a mosaic of oaks and chestnuts, and grassland. He saw opportunity. He saw water and timber and fertility—the necessary building blocks for an agrarian civilization. He saw natural capital. The first night, Potter and his assistant scavenged flesh from the hide of a dried beaver, and the next day the men fled east to return to settled lands along the Susquehanna River. Following the discovery, forts were built, natives removed, fields plowed and planted, forests cut, homes and towns built, roads developed—the valley was settled by Europeans.
Two hundred and fifty years later, what has become of this Empire founded on limestone bedrock? Of the natural capital that Potter saw, what did we spend and what did we invest? Beneath the imprint of agriculture, beneath the industrial and post-industrial world, the limestone remains. In places, geologists argue, the limestone is two-kilometers thick beneath the valley floor.