That is very neat about the free pass to national parks!

Gorgeous photos! We have a cavern near us, but it is not anything like that size.

That's weird about the date. My first thought was the time change, but it wouldn't be that big. (Once we went from EST to CT on a trip and were confused about the clocks in our hotel room being 'wrong', lol! We changed them to the 'correct' time, then had to change them back when we figured out what was going on. *g*)