It looks like all US national parks are being converted from leisure=park to leisure=nature_preserve.
The wiki doesn't give clear instructions about whether or not that's not the official way to do it. In official US NPS parlance, a nature preserve is not quite the same as a national park, but I understand that's not really the point. However, whereas the park region used to be rendered in this nice, understated transparent light green (very similar to official NPS maps actually), the nature_preserve has this butt ugly high saturation green with, at higher zoom level, an equally ugly 'NR' grid rendered onto it.
I know, I know, don't tag with the renderer in mind, but won't someone please think about esthetic sensibilities and all that?