What size can you camper be

They have several different options.

Ours is 36 ft and it was a perfect fit with lots of extra room

There are sites available in the campground that can accommodate the largest of rigs, but not all of them.

If you go to recreation.gov it will give you the max length for each site. From having been there, I believe there are some fairly deep sites. We are 36' and fit beautifully.