I try to do this at most places I go to.
Delaware
Brandywine Zoo - ZooChat I did every exhibit, plus playgrounds and some of the path (it's a straight line with a small loop at the end). They are currently undergoing a lot of construction with a big master plan; the llama yard is already gone, with a Madagascar building replacing it. All photos older than mine are out of date (they no longer have tigers, otters, etc.)
Maryland
The Maryland Zoo in Baltimore - ZooChat I did probably 90% of exhibits, except for some reptiles in the cave and in the tree. When I went, the lions and elephants were closed, along with most of the giraffe area. Blospz has added photos of the new exhibits.
National Aquarium in Baltimore - ZooChat is probably complete. I included photos of every single tank.
Plumpton Park Zoo - ZooChat has everything, I think.
Salisbury Zoo - ZooChat Nearly 100% of entire zoo. Has everything except inside the small building (hadn't opened yet). Includes statues, pathways, outside of all buildings, etc. in order, going counter clock-wise around the zoo.
New Jersey
https://www.zoochat.com/community/media/categories/adventure-aquarium.1475/ I did a lot of, but getting photos without other people in them is an issue here. There's at least a representative photo for all of the exhibits, if not one of each individual tank.
Pennsylvania
https://www.zoochat.com/community/media/categories/lehigh-valley-zoo.1630/ is complete.
https://www.zoochat.com/community/media/categories/philadelphia-zoo.1263/ Is probably at 100% of exhibits, except for any reptile changes in the last couple of months. Along with main exhibits I've done the inside of the KidZooU building, a lot of the reptiles, and the 360 trails, in particular.
https://www.zoochat.com/community/media/categories/zooamerica.2071/ looks complete.
Virginia
https://www.zoochat.com/community/media/categories/leesburg-animal-park.3285/ is complete except for on lemur island, which was closed.
https://www.zoochat.com/community/media/categories/luray-zoo.3554/ Has every outdoor exhibit and most indoors (snakes are all in the same settings).
https://www.zoochat.com/community/media/categories/metro-richmond-zoo.2593/ I did almost all of, there's a few reptiles missing from the gallery, probably a few primates (there's several spots where there's rows of enclosures that are exactly the same, except for species). Didn't go in bat building.
https://www.zoochat.com/community/media/categories/roers-zoofari.1633/ has everything.
https://www.zoochat.com/community/media/categories/virginia-living-museum.1469/ I'd put around 90%, as well. Another place where people were an issue indoors.
https://www.zoochat.com/community/media/categories/virginia-safari-park.3551/ is complete except for inside the larger aviary (closed) and a few of the reptiles (glare). Reptiles all look like the representative ones I did post.
https://www.zoochat.com/community/media/categories/virginia-zoo.1470/ Looks complete, except for some individual reptiles (there's a lot of species in the reptile building).
Colorado
https://www.zoochat.com/community/media/categories/downtown-aquarium-denver.1477/ is likely complete.
Nebraska
https://www.zoochat.com/community/m...s-conservation-park-and-wildlife-safari.2592/ is mostly complete, for the public areas. Could use a few photos of the gift shop/eatery/reptile building, along with some broader yard views. Each species has a lot of room to roam.