There are things about Arizona that still mystify me... I guess us Native Californians just expect the whole country to be run the same way CA is... Arizona is so different in that way. They like to be rebels here and I'm really learning to love that about AZ!
In CA, if you had a natural cave like this one, you would close it down, rope it off and not let anyone touch it or hike through it until the forest rangers had charged you $20 and then created a 12 inch wide path for you to walk on.... making sure you didn't touch one inch of the interior. In Arizona, they seem to be all about getting in "touch" with Nature... down and dirty style. So after driving over 100 miles, they pulled off to the side of the road and went caving... and they got DIRTY! I think they brought home half the cave with them. Here's the group in the BEFORE picture:

Here's the group AFTER:
Hanging out inside the caves:
Someday I'll tell you about "dispersed" camping... another odd (but interesting) thing about Arizona!