The cave was formed in limestone, probably by a combination of water erosion and tectonic activity. All of the speleothems dated older than 300,000 years ago, indicating that the cave has been actively forming speleothems for hundreds of thousands of years. The cave is subdivided into five distinct chambers. Most of the sediment in Mineral Hill Cave consists of limestone spalls, pieces of broken speleothems, and wet clay.
Large boulders are also present in most of the chambers.
Much of the clay probably washed into the cave periodically in the past, perhaps from other, now-collapsed entrances. This is a U.S. Government Computer System. Before continuing, please read this disclaimer and privacy statement.