A few days ago I found something a little weird. The geographic options for lat/long were missing. At first I thought that I just couldn't make anything into lat/long unless Tableau auto-recognized some fields as lat/long...
...but It turns out that you just need to change the data type to number (decimal or whole) BEFORE trying to make it geographic latitude or longitude. It seems this is just the way the GUI works.
2 answers
Yes, I solved it as I was writing the post. I thought I would just post it in case anyone else runs into the same situation