Dodge Rare Animal Conservation Center

This is first major exhibit building once you enter the gates, the only thing before it is the Spider Monkey exhibit. It focuses on rare and threatened/endangered animals with a few exceptions.

Is this where the zoo keeps their douc langurs? If so, how is their exhibit?

You are correct, this is where the Douc Langurs are exhibited. All of the exhibits for larger primates (douc langurs, red-capped mangabey, and blue-eyed black lemurs) all have rather generic, sterile exhibits, with red tile floors being the most disappointing part. The langurs are given access to two adjoining exhibits, one of which is half-covered by a large shade for "privacy." The langurs can be shifted to one side or the other if the keeper needs to go in to the other part of the exhibit. The cage furniture throughout this building gets changed regularly and new enrichment objects are given frequently.
I've been having issues uploading any more pictures than the ones I already uploaded but I can post pictures later on.

Thanks! So they don't have outdoor exhibit?

They might, but it's not one that's visible to guests. There are some off-exhibit spaces which are outside behind the building, I know there are some for the marmosets and the Red-capped Mangabey, but not sure about the langurs.

And to think that Chimpanzees, Gorillas, and Orangutans were once kept here... Sheesh!