Does not seem to be a master thread here. Anyone know if infants are allowed in the Mammoth Caves National Park tours?
Depends on the tour. Check https://www.recreation.gov/ticket/facility/234640 for your specific tour.
It does not specify, just says "Children 5 and under do not require a reservation or ticket.".
I tend to answer my own questions, after a little bit of research I simply called them and asked.