in the four times that I have been on the MMWT, I have never seen a Ranger.
Last year, at trail crest I noticed that I had left my tag on my backpack and didn't transfer it to my daypack. I figured that if I was confronted, that the ranger might cut me a break. But otherwise, it was a little bit too late to turn back to get the tag.
Long story short...no ranger, so no worries....this time.