The rocks of the Niagara Escarpment were formed in the middle of the Silurian Period (c. 443 to c. 412 million years ago) and were exposed during periods of glaciation that prevented and removed subsequent geologic depositions as recently as 11,000 years ago in the northern Midwest. The Arc of the Escarpment invites us to discover nearly hidden evidence of the Escarpment, ascend to cliff tops, descend to the base of cliffs, crawl into sinkhole-formed...