I think St. Louis may have America's best black rhino exhibit. This is really lush, and actually replicates the African woodland black rhinos are native to quite well.
@BlackRhino: you would love the "River's Edge" section of the Saint Louis Zoo, as there is America's #1 Asian elephant exhibit (actually 3 enclosures), possibly the #1 black rhino exhibit, and a strong contender for the #1 Nile hippo exhibit. On top of that there are spotted hyenas, dwarf mongoose, cheetahs, giant anteaters, capybaras, bush dogs, etc, all in naturalistic environments.
Two of the #1 exhibits for two of my favorite animals. I think this may be my new favorite zoo! Would you say River's Edge is a contender for one of the top 25 exhibits in America? because from your description and the pictures along with a documentary I saw of it on 'Ultimate Zoo' it sure seems like it to me.
River's Edge is a lock for a spot on my top 25 exhibit list, and it was also on each of the lists by the authors of "America's Best Zoos". It is rare to find a zoo with a number of world-class pachyderm exhibits!