Beginning more than a million years ago, at least four major continental ice sheets advanced into Ohio. The most recent glacier, named the Wisconsinin, bulldozed its way south from eastern Canada and lumbered across much of North America about 25,000 years ago. The belts of kames in this area of Stark county provide an extensive aquifer. These highly permeable gravel deposits readily absorb surface water and then hold it in staggering quantities as groundwater. Whenever this groundwater reaches the surface, as it does here in Jackson Bog, artesian springs and seeps result.
Springs emerge from beneath the elongated kame that borders the northern edge of the preserve.
It is these gravel deposits with their corresponding springs that hold the key to the very existence of Jackson Bog, as well as to its future.