Finally, a controversial pick! I've been surprised how agreed upon every choice has been so far, it's been getting a little boring as far as I’m concerned.


In my opinion White Oak definitely deserves to be featured on this list and I fully realize some will disagree which is completely ok. Friendly debate is what makes threads like these so interesting and I'll gladly defend my position.
Just to make it clear, are you suggesting that facilities only open by guided tour should be disqualified? If so, I definitely disagree. Any and all American zoological institutions are eligible to be featured and micromanaging what should be allowed seems counterproductive to creating a list showing the true diversity of American collections. I see no reason why facilities only seen through a reserved tour shouldn't be included, as they all have the potential to be just as "must-see" as any traditional zoo. I'll say now there is one other facility later on this list that is only open by reservation and I will be curious to see if it gets the same amount of pushback as this one.
The pricing is definitely very high, no denying that and I understand that it's not something everyone can afford or be willing to spend. With that said, cost and worth are very subjective factors that are decided on an individual basis. I'm sure there are some who will read this list and won't be willing to spend money to see Disney, SeaWorld, or even the San Diego parks, but that doesn't make them any less "must-see."
In what way? It could just as easily be argued that the California Academy of Sciences or Disney's Animal Kingdom might not count as a zoo for a variety of different reasons. The term zoo is pretty all-encompassing in the context of this thread and I struggle to see how a facility that can be visited by the public and includes elephant, giraffe, rhino, tiger, etc, somehow isn't a zoo.
When choosing what places made the list I didn't just consider if it had a vast collection of rarities or several top-notch exhibits. A big part of the decision making process was if it provided a unique experience, which this one definitely does. The western hemisphere's largest elephant herd, a variety of rare hoofstock, terrific enclosures that use the natural landscape, and the amazing breeding records are all just gravy. I think even those who disagree with it's inclusion can't argue that.