Wyandotte Caves were designated a National Natural Landmark in 1972, and they are now part of O'Bannon Woods State Park.

As the glaciers melted, the icy cold water flowing towards the Ohio River (which was then much higher than it is now) dissolved the limestone which is the bedrock for much of Southern Indiana, hollowing out caves such as Wyandotte.

Wyandotte Cave was used by Native Americans for nearly 4000 years before Europeans arrived in the area; carbon dating of artifacts provided evidence of human activity potentially as far back as 8000 BC.

The Native Americans used torches made of hickory bark and grape vines to light the cave where they mined for aragonite, which they used for pipes and necklaces, and chert, which they used to make stone tools.

Shortly thereafter Wyandotte Cave became known as an excellent source of saltpeter, an integral component of gunpowder, and of Epsom salts, which have medical uses.

Modern tours feature Dr. Adams' vats and hoppers, and point out where magnesium sulfate (the chemical name of Epsom salt) is visible as a glittery substance lining the cave walls.

The caves were closed to visitation from 2009 to 2016 in order to slow the spread of white-nose syndrome affecting the bat population.

[8] After eight years, the agencies studying the bats gave the "okay" to open up the caves, as long as "decontamination stations" were walked through at the end of each tour.

State Representative Lloyd Arnold (R-74) and Lieutenant Governor Eric Holcomb showcased the $1.7 million project to replace the main building on-site and re-wire the interior of the cave.

The presence of hibernating bats in the winter is the main reason that the caves are closed to the public from the first of November until February 28.

Bats can occasionally be seen by the lucky visitor during the rest of the year, but they are far less numerous and less likely to be disturbed in the warmer months.