Filled die. I bet if you look at it under a magnifying glass you can probably see a slight remnant of the MM (I think I can see a P, but the pics are blurry). I recently found a 2014 Smokey Mountains Quarter that looks like yours. P was filled.
Thanks guys. That's what I kind of thought. Wanted to check with the experts. And you're right @Oldhoopster, I can see a very faint P under the scope.