[4][5] The sinkhole was formed by subsidence into caverns of paleokarst composed of Redwall Limestone of the Pennsylvanian subperiod.

In addition, many of the surfaces on the south wall also contained a patina of manganese oxide, inferring that the area was exposed over a few hundred years.

[6] The walls on the upper area of the sinkhole are made out of sandstone from the Schnebly Hill Formation, while the lower areas are made from shaly siltstone of the Hermit Formation.

A second collapse happened in late 1989, opening the cave by around forty percent in the northern section.

[1][7] The United States Forest Service conducted a geologic study of the sinkhole in 1990 to prevent visitors from falling victim to a spontaneous sinkhole forming.