When I was stationed at Ft. Leonard Wood, I took charge of organized caving in Pulaski County. Missouri is home to around 8,000 caves. I discovered six while I was there. The "NSS" in the photo stands for National Speleological Society. While there, I did cave mapping and conducted bat surveys. We also did cave rescues. The photo was taken inside Barry Cave, MO, but if you google it, the cave won't come up as a known entity in Missouri. But I assure you, it's there.