Thanks to everybody for participating. I got a grand total of 10 submissions – close to double the number I got from the previous UK challenge and with most of them submitted in the first 2-3 days. The winner of the US Zoo Map Challenge is
@TinoPup, who correctly guessed 48 out of 50 answers and ended up with a total score of 48.25/50. Congratulations to our winner

As this challenge is more about testing your own knowledge than competing, I will not be posting any ranks or standings. I hope that no matter what your score ultimately ends up being, you all enjoyed participating

I plan to get everyone's individual scores out to them by the end of today; they are completed but I still need to add some notes and format them.
Before I get to the answers and analysis, I have an announcement to make: I mistook #22 for another facility and placed it in the wrong location; the correct location should have been in the outskirts of Austin, Texas, rather than near the Gulf Coast. A further explanation of this will be provided; as far as I can tell, everyone who was affected by my mistake has been given full credit for their answer.
But let’s cut to the chase: here are all of the answers and the clues that they match with. They are listed in numerical order, with the clue coming first and the answer second:
Clue: this zoo’s attendance numbers have been falling in recent years, and are nowhere near what they were a century ago when it was free
Answer: #1 Franklin Park Zoo (substitutions accepted: Capron Park Zoo, Stone Zoo, Roger Williams Park Zoo, New England Aquarium)
Clue: one of only two facilities to hold Steller sea lion and one of a handful to hold belugas
Additional Clue: “two facilities are named for their cities/towns, but both have under 20,000 residents…”
Answer: #2 Mystic Aquarium
Clue: only zoo in the US that is located at a K-12 school
Answer: #3 Trevor Zoo at Millbrook School (substitutions accepted: Livingston Ripley Waterfowl Conservancy)
Clue: is home to a white-winged vampire bat and one of the country’s few breeding herds of Thorold’s white-lipped deer
Answer: #4 Rosamond Gifford Zoo
Clue: the 2 out of 5 zoos that *aren’t* named for their respective borough in this major city
Answer: #5 Central Park Zoo and #6 Prospect Park Zoo (substitutions accepted: New York Aquarium, Bronx Zoo)
Clue: DISCO HIPPOS!
Answer: #7 Adventure Aquarium
Clue: a patriotic zoo, in a town long associated with chocolate [POST NOTE: the town is Hershey, Pennsylvania – home of the Hershey Company, which also founded and controls the zoo)
Answer: #8 Zooamerica
Clue: despite its name, this bird-focused facility is not located in or close to Washington DC [POST NOTE: it’s a few hours away in Pittsburgh and is not associated with the federal government at all]
Answer: #9 National Aviary
Clue: a large rural conservation center that is not only well-known for breeding hoofstock and carnivores, but also amphibians and beetles
Answer: #10 The Wilds
Clue: one of the world’s largest waterfowl collections – the American Slimbridge, if you will
Answer: #11 Sylvan Heights Bird Park
Clue: 250-300 strepsirrhine primates live at this tour-based research facility, and it was once home to the world’s only talking lemur [POST NOTE: that lemur and the name of his show was Zoboomafoo, and the show was filmed on-location at this facility]
Answer: #12 Duke Lemur Center
Clue: named for where it sits adjacent a body of water, this zoo is pretty southerly and humid for Antarctic penguins and Amur tiger but it makes it work
Answer: #13 Riverbanks Zoo
Clue: has one of the world’s largest orchid collections – is unfortunately also remembered as the site of a recent extinction [POST NOTE: the species that went extinct here was the Rabbs’ fringe-limbed tree frog; the second-to-last one died at Zoo Atlanta]
Additional Clues: “These numbers correspond to zoological facilities (well, almost all of them are zoological in nature…” and “the final one is named after a major city… but beware, as this facility is not mainly zoological in nature”
#14 Atlanta Botanical Garden (substitutions accepted: Zoo Atlanta)
Clue: one of America’s two community college zoos and a world-renowned bat conservation and breeding center are located in the same town [POST NOTE: the town is Gainesville, Florida – home of the University of Florida]
Answer: #15 Santa Fe College Teaching Zoo and #16 Lubee Bat Conservancy (substitutions accepted: Carson Springs Wildlife Conservation Foundation)
Clue: much like the WCS in New York, this organization named for a famous naturalist is responsible for the zoo, aquarium, and two other facilities in a single city. NOTE: only 1 of the 2 “other facilities” need to be provided
Answer: #17 Audubon Zoo, #18 Audubon Aquarium of the Americas, and #19 Audubon Insectarium OR Freeport-McMoran Audubon Species Survival Center
Clue: this rural conservation center is one of the most successful cheetah breeding centers in the world
Answer: #20 Fossil Rim Wildlife Center
Clue: a coastal tourist destination and an architectural ode to Ancient Egypt [POST NOTE: … in that the facility consists of three glass pyramids]
Answer: #21 Moody Gardens (substitutions accepted: Crocodile Encounter)
Clue: this misleadingly named zoo became famous on social media for its blue Jello-devouring hippopotamus [POST NOTE: refer to beginning of this post. I made an error with this clue. For apparently several years now I have been mistaking the Texas Zoo for the Capital of Texas Zoo; as such, the clue was referring to the latter but the bubble is actually the location for the former. The Capital of Texas Zoo is indeed located in the outskirts of Texas’s capital city, Austin, so it is *not* misleadingly named. The Jello-eating hippo is definitely true, though… anyway, a few people correctly guessed Capital of Texas Zoo while one person guessed the Texas Zoo; all of these people have been given full credit. If you missed this clue because you didn’t see the bubble in Austin, feel free to give yourself an extra point for it ]
Additional Clue that in retrospect was also wrong: “another has the name of a state in it, but is a lesser-known facility and the name will distinctly not help you place it within the state”
Answer: #22 Capital of Texas Zoo
Clue: named for and financed by members of the family who founded J.C. Penney, this zoo is well-known on ZC for its holdover collection of unusual animals like bearded pigs, pileated gibbons and rare duikers
Answer: #23 Gladys Porter Zoo
Clue: home to the only sitatunga walkthrough in the country
Answer: #24 Mesker Park Zoo
Clue: 2 major zoos and 1 major aquarium in the same place – a great deal, if you can brave the wind
Additional Clue: two facilities are named for their cities/towns, but both have under 20,000 residents (and the larger one is more often associated with the large city next to it) [POST NOTE: the town is Brookfield, Illinois]
Answer: #25 Brookfield Zoo, #26 Lincoln Park Zoo, and #27 Shedd Aquarium
Clue: this museum-aquarium combo also serves as its state’s only public aquarium
Answer: #28 National Mississippi River Musem & Aquarium
Clue: this free zoo holds one of only two successful breeding pairs of emperor tamarin in the country [POST NOTE: the other is Racine Zoo in Wisconsin]
Answer: #29 Como Park Zoo (substitutions accepted: Minnesota Zoo)
Clue: this zoo-aquarium pair both make reference to the lake their city sits on
Answers: #30 Lake Superior Zoo and #31 Great Lakes Aquarium
Clue: one of the only zoos left in the country breeding Japanese Serow
Answer: #32 Roosevelt Park Zoo
Clue: half of this facility is a natural history museum with taxidermy specimens
Answer: #33 Great Plains Zoo
Clue: this large reptile park is very close to a famous American landmark [POST NOTE: that landmark is Mount Rushmore in South Dakota]
Answer: #34 Reptile Gardens
Clue: one of the newest facilities on this list, this rural zoo only opened in 1999
Answer: #35 Rolling Hills Zoo
Clue: one of several free zoos in the Midwest, located in a small town but still held elephants until 2015
Answer: #36 Lee Richardson Zoo
Clue: this zoo is known for its steep elevation, breeding record with giraffe, and for a brand-new, much-praised new exhibit complex
Answer: #37 Cheyenne Mountain Zoo
Clue: there are two facilities on here that almost have the same name, and which are routinely confused with each other
Additional Clue: “Make sure that you provide enough of the zoo’s name for me to know which one you are referring to (in case, perhaps, there are two with very similar names – free hint!)”
First Answer: #38 Living Desert Zoo & Gardens State Park
Clue: the only tribally owned zoo in the country, which labels its exhibits in the tribe’s native language
Answer: #39 Navajo Nation Zoo
Clue: this aquarium that opened in its current location in 2014 – and this specialty facility that opened in 1938 – are located in the same urban area whose major zoo I left off the list
Answer: #40 Loveland Living Planet Aquarium and #41 Tracy Aviary (substitutions accepted: Hogle Zoo)
Clue: this aquarium inside a casino has one of the country’s largest tanks, a shipwreck that once held a great hammerhead shark
Answer: #42 Shark Reef Aquarium at Mandalay Bay
Clue: there are two facilities on here that almost have the same name, and which are routinely confused with each other
Additional Clue: “Make sure that you provide enough of the zoo’s name for me to know which one you are referring to (in case, perhaps, there are two with very similar names – free hint!)”
Second Answer: #43 The Living Desert
Clue: perhaps the least well-known zoological facility in its urban area, this aquarium is nevertheless operated by one of the most renowned marine biology institutes in the world
Answer: #44 Birch Aquarium at Scripps Institute of Oceanography (substitutions accepted: SeaWorld San Diego)
Clue: the only free public aquarium in the country
Answer: #45 Cabrillo Marine Aquarium (substitutions accepted: Aquarium of the Pacific)
Clue: named for the large trees surrounding the zoo and its picturesque coastal town
Answer: #46 Sequoia Park Zoo
Clue: three facilities in one urban area – one a leader in tree kangaroo conservation, another has two aquariums, and the third has a tram tour through 435 acres of free-range space for native animals
Answer: #47 Woodland Park Zoo, #48 Point Defiance Zoo & Aquarium (should be plural now, I guess

),
and #49 Northwest Trek Wildlife Park (substitutions accepted: Seattle Aquarium)
Clue: the second-oldest public aquarium in the country opened before the state it’s located in was even a state
Answer: #50 Waikiki Aquarium