I think the lower 48 don't need any more full sized maps, but there is one type of very unique habitat that I'd completely miss that would make for a great park. Some animals that could be featured on such a map are
Big game
-plains bison 🦬
-pronghorn
Small game
-coyote
-american badger*
-swift fox*
-black tailed prairie dog *
Upland game birds
-hungarian partridge*
-lesser prairie chicken*
-greater prairie chicken*
-sharp tailed grouse*
-greater sage grouse*
Waterfowl
-sandhill crane*
-blue winged teal*
-shoveler*
-bufflehead*
-snow goose