The exact number of individuals who entered the cave during those three millennia is unknowable.

But the evidence they left — the thousands of artifacts documented throughout the cave passages — suggests this was not the activity of a handful of adventurous individuals.

It was, by the archaeological evidence, a systematic operation.

More Than Nineteen Miles Of Ancient Darkness

The NPS statement that prehistoric American Indians explored more than 19 miles of Mammoth Cave’s passages is a figure worth dwelling on.

Nineteen miles is the measured length of passages where archaeological evidence — torches, artifacts, footprints, mining marks — has confirmed human presence.