Atrocious
31. Pocono Snake & Animal Farm (haven't been in several years, but so far in my life, the only zoo I'd actually call "bad," "horrible" even. Roadside kind of place with lousy outdoor exhibits [emu, bobcat or lynx, black bear] as well as classic roadside zoo primates like ringtail lemurs.)
Mediocre (almost bad or just meh)
30. Bird Kingdom (Niagara Falls, Canada. Went once years ago. Don't remember much, but it was alright I suppose)
29. Center for Science Teaching and Learning at Tanglewood Preserve [CSTL] (I volunteered at this small preserve on Long Island with owls, goats, and small exotic-pet type far. Not impressive, but I promise it isn't actually bad. They have since opened new exhibits for emu and other animals, but I have not seen them yet.)
28. Holtsville Ecology Center (more of a rescue place than an actual zoo. Haven't been in years, but they have some unique creatures for a Long Island attraction [hoping they still have these]: black bear, puma, binturong, and a genet [most likely common, but I forgot])
27. Long Island Game Farm (meh, a kiddie kind of place with meh spaces for their animals)
26. Seneca Park Zoo (it's cool that they have the only African elephants in New York, but I swear those girls are on borrowed time. I think an expanded savannah habitat was not a good idea, putting giraffes indoors for most of the year ala Buffalo. They should phase out elephants one day and focus on rhinos or even pygmy hippos. The zoo is small and narrowly shaped, so it's difficult to give any large animal a lot of space, but they really ought to consider paring down their large mammal collection. Thank god they nixed gorillas from their tropics exhibit.)
25. Staten Island Zoo (I've only been there once a long time ago so I cannot judge it fairly, but I recall the otter exhibit not being good. Amur leopards were the only animal young-teen me thought was impressive. I want very much to go back one day, perhaps this summer, but going there from Long Island is hassle, and now the city and subways are so unsafe I don't feel ready to do that yet.)
24. Buffalo Zoo (It pains me to put Buffalo in this category, but the zoo showing its age and has a lot of warm-weather fauna in just adequate spaces, not to mention the gorillas)
23. ZooAmerica (only been once. Hershey Park's itty bitty hidden zoo about American wildlife has a surprising array of rare and less-represented fauna such as thick-billed parrots, black-footed ferrets, and ringtails as well as elk, pronghorn, wolves, and bears. This much packed into a small space leads to what I perceive to be unaesthetically pleasing facilities. The indoor spaces, however, were alright. The desert exhibit was probably my favorite exhibit.)
Good/okay (nice places, but not necessarily outstanding)
22. Philadelphia Zoo (only been once several years ago. America's [arguably] first zoo needs some reorganizing, particularly Africa. Zoo360 is an impressive innovation and I hope they expand it to include hoofstock etc. like they planned to do for years.)
21. Prospect Park Zoo (haven't been in a while, but hoping to go again one day. Although the zoo has nice highlights in hamadryas baboons, dingoes, Pallas' cats, and tufted deer, I think the zoo ought to have a central theme like Queens does to make its collection seem more coherent and organized)
20. Franklin Park Zoo (nice African hoofstock yards, big cat exhibits [in my opinion], and Australia section, but I think FPZ is squandering its potential to turn its empty space into Boston's answer lauded zoos like Bronx, Washington, or Atlanta.)
19. Toledo Zoo (lots of ABCs- and warm-weather ones at that- hodgepodged into their bisected space. Still, plenty of unique creatures, especially a wide array of Australian fauna)
18. Cincinnati Zoo (the pessimist in me wants to say "overrated", but that is largely due to my opinion of the direction the zoo is going with its master plan as well as some of the spaces for its current animals and declining of rare species)
17. Akron (only went once while they built the new Africa exhibit. Nice midsized zoo with some nice exhibits for large carnivores, North American avians, and a nice herptile house. An up and comer in America's zoos)
16. Rosamond Gifford (only went once several years ago. Home to arguably America's most successful Asian elephant breeding program and impressive exhibits for cold-weather fauna, particularly rare ones like white-lipped deer. They released a master plan in 2014 advertising an even larger elephant habitat as well as an Africa exhibit. These additions would put RGZ among America's top-tier zoos)
15. Central Park (New York City proper's zoo is tiny but mighty. Japanese macaques, penguins, tropical birds, and rare ducks feature prominently at this storied zoo)
14. Brookfield (Chicago's storied second zoo is significantly larger than that in Chicago proper, but budget cuts have kept Brookfield from tapping into its potential for huge spaces for many creatures. Their Australia, swamp, bear, wolf, and Africa exhibits are wonderful. I have never seen okapis indoors before or since Brookfield.)
13. Louisville Zoo (Kentucky's premiere zoo boasts a large size, innovative rotation exhibits, and the only oriental stork in America. It's South America exhibit is bad except for the guanaco exhibit and Africa could use some solid organization. It's elephant program seems up in the air to me. They renovated their space and AI'd the female African, but they still have 1.1 African and 0.1 Asian. What do they want to do with them? Their 2016 master plan is impressive and I hope they complete it as intended)
12. Queens Zoo (an all outdoor zoo with a clear focus and wonderful faunal variety such as pudu, spectacled bear, and coyote)
Great
11. Houston Zoo (only been once, and a rushed visit at that. A mid-sized zoo in America's fourth-largest city, the lushly-planted Houston Zoo boasts a platinum-tier Asian elephant breeding program in a silver to gold-tier exhibit, although it feels out of place in the presence of the lovely Africa exhibit and primate area [the latter of which I did not see]. The red panda exhibit also felt out of place, and the sea lion exhibit didn't strike me as great. I visited while the Texas Wetlands exhibit was being constructed, so I cannot judge that or the new Pantanal exhibit. I know sea lion exhibit changes are slated to happen as well.)
10. San Diego Zoo (I do not think I can judge SDZ fairly. I went once at least a decade ago and much has changed since then. I don't remember a lot, but 13-year-old me was impressed for sure. I think I recall the giraffe and rhino exhibits being small for my taste, though)
9. Cleveland Metroparks Zoo (Their Rainforest and Primate, Cat, and Aquatics buildings show great potential. It's also odd that the Rainforest is separate from the entrance. The rest of the zoo is solid by itself due to its mammal variety and large spaces)
8. Bronx Zoo (Bronx has a long history of breeding endangered animals and is particularly known rare hoofstock like gaur, rhim gazelles, and barasingha deer. Although budget cuts have prevented the zoo from updating its old facilities, most of the spaces are perfectly fine for most of their animals presently)
7. Smithsonian National Zoo (rightly treasured as one of America's most treasured zoos. Great Asia, reptile, and ape exhibits. Great cat exhibits are solid but maybe long in tooth. Think Tank is a good idea, but might go over the head of the average zoo-goer)
6. Fort Worth Zoo (where it hits, it hits hard. Where it misses, it misses hard. I felt horrible about their penguin exhibit. I feel like it's trying too hard to copy its neighbor to the east while it has plenty for space to forge its own identity)
5. ZooTampa (*trying hard to hide my bias as I interned there* Fantastic Africa and manatee exhibits, nice rhino and Australian exhibits, not a fan of the sun bear and tiger exhibits. The reptile and aquatics building [with the manatees] is also good. The new Florida wildlife exhibit was under construction during my time in Tampa, but judging by member photos, I cannot say I like them much)
A+ top tier
4. Detroit Zoo (welfare drives all zoos' decisions, but none more than Detroit. Huge spaces for their animals as well as an impressive variety make this a top-tier zoo in a place few laypeople would expect. I only don't rank it higher due to its large focus on warm-weather fauna, particularly since they made such a big deal over phasing out elephants due to climate)
3. Dallas Zoo (hands down the best elephant exhibit in any American zoo. Weaknesses: the zoo seems hyper-Africa-focused with other parts of the zoo being less organized)
2. Columbus Zoo & Aquarium (this huge zoo has large immersive spaces for its many diverse species. I can't pic a favorite because most of its areas (Heart of Africa, North America, Asia, Polar Frontier, Manatee Coast) are very strong. Moose, African leopard, manatee, wolverine, and wildebeest are some less-represented species that the zoo cares for. Apparent animal privacy and the exhibits for penguins, gorillas, and bonobos were issues in my opinion)
1. St. Louis Zoo (they have just about everything under the sun. A two-level reptile house, impressive large mammal habitats, and a wide array of less-represented hoofstock make St. Louis a great place)