In the beginning the waters of the Ohio and
Allegheny rivers
flowed northward to the St. Lawrence River. During the ice age, glaciers
pushed southward toward our area, and the great river valleys were filled
with rock and gravel. The bottom of our "Underground River" had been
formed (carved) milleniums ago by the northward flowing rivers.
The northward flow of the rivers was blocked by glaciers and new
outlets southward were created. Clay and silt were deposited over the
layers of gravel, sealing them off from the surface rivers formed
"shortly" thereafter. Through the deposit of gravel and rock our
"Underground River" flows at the slow rate of five or six miles a
day. (9)