We just got back from Yellowstone. I'm sure they're cool, but didnt really care about the visitor centers. We used this app called Gypsy Yellowstone. Linked to your gps the guy gives a tour all around the park. Used it all 3 days we were there. Since all the tours cancelled we had to do something else and that worked out great for us. Glad someone told us about it. Would have just been driving aimlessly around without it.
Just saw on the news that a bunch of buildings in Gardner MT. (North Gateway city where the Roosevelt Arch is) burned. That sucks. Cool town as well.
Check out the lodges in Yellowstone on their website. They just opened up some more rooms and cabins. You probably can get a spot in the park now.
As to masks, we spent the night in Jackson and they had masks in effect in restaurants and the like. Also in Yellowstone you need a mask to go into a building (food, gift etc..)