The site is under a rather slow and painful revision process by a new vendor. There is a long list of advanced functionalities that the NPS wants to implement over time.
Meanwhile, it has gone backwards. As an example, campsite maps and photos which used to be part of the site are still not available.
I wrote to the NPS project manager in Colorado the other day with a couple of comments and received a warm reply thanking me for providing such specific comments.
One of my comments was that the rows for each site are too tall, so less sites can be seen on the screen at a time. The other comment was that it would be very helpful to have a consistent table or calendar format for each park or facility showing the various reservation "seasons" for when sites are respectively 1) “reservable” (including how far in advance), 2) available as “walk-in”, and/or 3) “closed”.
Whether or not it will have positive results I can't say, but I figure it's the only chance we have to try and make things better. There is a link to "Submit Feedback" at the bottom of the home page under "Let Us Help You".
https://www.recreation.gov/feedback