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Saltpeter Cave

Site ID: 15Cr99

Niter Mine
Kentucky Archaeological Survey
Unless specified, we cannot provide site location information.


​​​​​​​​​​​​​​​​​In the early 1990s, archaeologists from the University of Kentucky investigated the remains of an early nineteenth-century saltpeter mining operation at Carter Caves State Resort Park. Saltpeter – potassium nitrate – is a major component in gunpowder.  The other two major ingredients are charcoal and sulphur.  

During the War of 1812, America had to produce its own gunpowder.  Fortunately, the soil in many of Kentucky's caves and rockshelters, such as Saltpeter Cave and the entrance to Mammoth Cave, were excellent sources of saltpeter.  As a result, miners removed over 300,000 pounds of this mineral from more than 150 Kentucky caves and rockshelters during this period.

Examination of the intact mining equipment in Saltpeter Cave revealed that an extensive War of 1812 mining operation took place within it.  This operation appeared to be unique in that it exhibited characteristics of both large-scale production mines and much smaller, cottage-industry mines.  Large-scale mining operations used large, box-shaped vats and pipes or troughs to pump water into the cave. Smaller operations exclusively used small, V-shaped vats and buckets to bring in water by hand​​.

Saltpeter Cave is listed in the National Register of Historic Places.​ Visitors to Carter Caves State Resort Park can take daily tours through Saltpeter Cave between Memorial Day and Labor Day.

An archaeologist documents a saltpeter vat.


The process of extracting saltpeter from cave soils involved mixing the soil with water in vats to create a solution, then adding a potash solution - made from soaking wood ash - ​to create saltpeter crystals.  

The archaeological remains associated with the mining operation at Saltpeter Cave consisted of 26 wooden leaching vats.  Excavations around several of the vats found that some had been constructed with horizontal planks to form a V-shaped wooden framework. Miners set up the framework over a wooden water trough or sat it directly on stones.  Wooden pipes, rather than buckets, were used to transport water to the vats at Saltpeter Cave. 

Drawing of a reconstructed saltpeter vat, based on archaeological remains.

What's Cool?

Impressions in the Soil

​Although much of the wood from the Saltpeter Cave vats has been removed over the years, a few areas in the cave retained some wooden elements.  

​Fortunately for researchers, impressions from the removed wooden planks and log framing were left in the soil. These impressions provided important information about vat size, shape, and building techniques.  Archaeologists successfully used this information to reconstruct replicas of the vats used during mining at Saltpeter Cave.​

The decomposed remains and discolored soil impression of a wooden saltpeter vat.

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