We salute New Mexico today, which joined up in 1912. A fine state with everything to recommend it, including much open space for the native Critter Population.
In 1901 a teen cowpoke named James L. White noticed a slew of bats coming out of the ground, and thus discovered the Carlsbad Caverns. He slithered down there, and over the next years lobbied (successfully) for recognition for this remarkable find. The Caverns are enormous, marvelous, and extensive.
Rhinos do not often go into caves, dreading the “lemon squeeze” factor, when you go through a tight space and get stuck. Clearly, the problem is more pressing (and common) when you are our size, yes?