A Window In Time… Ancient Bat Bones, Arrowheads, and Civil War Signatures

Caves are time capsules… with their rooms and passages protecting the remnants of their prior inhabitants for hundreds, if not thousands of years or more. The caves that reside in Mammoth Cave National Park are no exception. Recently, I had the privilege and opportunity to join Dr. Joe Douglas, historian caver Marion Smith, caver’s Kristen Bobo and Gerald Moni, as well as Larry Johnson and Alisa Cloutier of the National Park Service on a research trip to cave MACA#027 as part of a project researching the historical graffiti by Civil War era soldiers from 1860-1865 written on the interior walls of caves in the region.
We initially gathered at the park’s Science and Resource Management building and made our way to the river where on boarding the Park Service’s new flat bottom boat, we embarked on our trip along the Green River.

Ranger Larry Johnson approaching with the Park Service boat that took us to our destination.
Traveling along the Green River near Mammoth Cave National Park

After completing the voyage downriver, we exited the boat and made our way up the bluff and to the cave entrance which was gated to protect the biological and historical resources inside. At this point we unlocked the gate and were able to make our way into the cave’s interior.

The cave’s gated entrance

Immediately on entering there was clear evidence that there had been other occupants of this cave as nests were evident several feet up the walls… possibly that of an Eastern Phoebe which often nests in the entrance of caves.

Possibly an Eastern Phoebe nest

Moving along deeper into the cave’s interior was the first sign of human visitation and example of the caves time capsule-like nature… a single clam shell that Kristen pointed out and explained that it would have had to be brought in from the river, likely by a Native American where it would have been consumed during their time in the cave.

Single clamshell likely brought in by a Native American

Moving further in along the cave’s upper level, we came upon a piece of broken off chert… inconclusive, but still a potential sign that humans had entered the cave since Native American’s would often enter cave to obtain chert for the purpose of crafting arrow heads.

Broken off chert… another possible sign of Native American presence

Towards the back of the cave’s upper level, the passage narrows and becomes windy, leading to an dead end that contained the first historical graffiti we found, a signature from 1861, the name Doctor A. Blair being recognized on further post-trip research from the 1860 Federal Census. He and his wife and children lived in Edmondson County (the same as the cave), and he may have in fact lived near the cave. He was not a Doctor by profession however, with Doctor actually being his given name which had been suspected by historian Marion Smith.

There was also an individual by the surname of Houchins. In fact, in local lore an earlier Houchins is reported to have “discovered” the historic entrance to Mammoth Cave around 1799 though it is likely that it was known earlier, especially by Native Americans who were present in the late Archaic period.

Winding passage
1861 Civil War era cave graffiti including that of Doctor A. Blair

After finding the initial example of Civil War era graffiti, we moved back towards the entrance and down the crevice into the cave’s lower region.

Moving down through a crevice leading to the lower levels of the cave
Cave Cricket found along the way
Final ledge leading to the lower level of the cave. It was possible to
climb down unassisted but a rope was used for added safety.

On reaching the lower level, a small waterfall was noted in the corner and the room was sloped downward on loose rock. Moving down the slope you can see in photos that there were broken pieces of a Civil War era wooden ladder that was likely placed where our rope was.

Small waterfall
Sloping floor made of loose rock
The broken remnants of a Civil War era wood ladder

Slowly moving down the rocky slope, Dr. Douglas and Kristen Bobo found additional bits of evidence showing that Native American’s were once present in this cave. Among the evidence were several arrow heads… I consulted an archaeologist on the one in the photo below and it’s thought that it is Archaic Period, between 4,000-6,000 years old. Also among the rocks were aquatic snail shells that would have also had to be brought in from the river below.

An arrowhead, possibly Archaic at 4-6,000 years old
Aquatic snail shells

Otherwise, we also noticed that various animals had recently made their way into the cave.

A random frog…
Remains of an animal, possibly a possum

As we completed the scan of the rocky slope for artifacts, we noticed additional Civil War era graffiti on the walls on the far side of the room, another signature from 1861, and another outside of the target range dated 1873. Of note and as an update to this post, the great great grandson of Thomas E. Lee responded on seeing this post. His great great grandfather had been an early guide/explorer is what is now Mammoth Cave National Park and recognized the signature as his which prompted me to find this post (link) for added backstory.

Others were present but many were too recent to be relevant for the project.

Civil War era graffiti from 1861
Historical graffiti from 1873, not quite in our target range

Once notes and photographs of the graffiti were taken we moved further in until there was a split in the passageway. Both involved crawls, though the way to the right was a far tighter squeeze. Reports are that in 1935, before Mammoth Cave was officially designated as a National Park, Claude Hibbard and geologist E.R. Pohl found that both passages had been blasted shut, though for no definitive reason. At some point afterwards the passages were opened though the right side, the B survey, is an extremely tight squeeze. At this point we chose to follow the A survey passage to the left and began the crawl through what is one of the primary points of interest in the cave…

Progressing through the crawl, tiny needle like protrusions from the wall become apparent. These are in fact a deposit of bat bones, first studied by a researcher (Thomas Jegla) in 1960. Jegla counted humeri and measured skulls and concluded that they were Myotis sodalis, Indiana Bats. In the mid-1990’s, Mammoth Cave Park Ecologist Rick Olson and Illinois State Museum researcher Dr. Rick Toomey, now with the National Park Service proposed another examination. It was initially thought that the bone bed was created from a single, catastrophic kill event due to flooding, but it is now thought that it occured over multiple events over the last 10,800 years. Sedimentation rates (rate at which dirt covered the layers) weren’t uniform but the earliest event likely occurred 10,800 years ago and the most recent 2,200.

Ancient Bat Humeri
Ancient Bat Humeri

Continuing on past the bone bed, we continued through the A Survey passage, scanning for graffiti of Civil War era signatures along the way and taking in the cave’s sights including beautiful flowstone formations and a dome as well as additional biological resources.

Inspecting Cave Graffiti
1869 signature, just outside the target dates
Flowstone Formation
Large Flowstone Formations
A Survey Passage
Cave Beetle
One of the cave’s domes
Cave Salamander
Dr. Douglas and Marion Smith inspecting graffiti

On reaching the end of the A Survey, half of the group made their way back to the cave’s entrance to secure transportation back while the other half made a brief trip through the tight passages of the B Survey to look for additional examples of historical graffiti with minimal success. Once complete we made our way back up the rocky slope to the caves upper level to meet up with the rest of the crew.

Alisa Cloutier making her way out of the tight B survey passages
Marion Smith in the tight squeeze of the B Survey passage
Making the hike back up the rocky slope of the caves lower level
and back up to the upper level exit.

On exiting the cave, the gate was secured to ensure the protection of its contents well into the future and made our way down the bluff and back to where the boat awaited our return after this 5 1/2 hour expedition. Making our way back up the Green River was a pleasure considering the incredible view and breeze as we sped around each bend.

Please note that caving can be a dangerous activity for the inexperienced. If you have an interest in exploring caves, check out a local grotto from the National Speleological Society website so you can connect with experienced cavers in your area who will show you the ropes. Also, remember that caves can be on either private property or government land so please always ensure that you either have permission from the landowner or the proper permits obtained before visiting a cave. While there, remember to…

Take nothing but pictures.

Leave nothing but footprints.

Kill nothing but time.


  1. Sheila Minor
    July 21, 2017 / 7:52 am

    Absolutely Beautiful. Thank you so much for sharing your journeys with us.

    • Larry Matthews
      July 21, 2017 / 1:15 pm

      Very interesting and great photos !!!

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