When I visited in 2019, I was told that the zoo had 18 Squirrel Monkeys and that the primates were fully free. They could leave the grounds if they wished, but were content to stay fed and close to their home. Apparently there really isn't any traditional "exhibit" and instead the monkeys can go wherever they like! Although, they do have an indoor area that they can retreat to when it gets cold.
Indeed there are no true barriers to the enclosure, which was slightly confusing to me. At first I assumed there may have been some invisible electric fencing, but it seems they may truly be free-roaming. Interesting to see they seem to have their own territory then, since they don't go past a certain point (I've never seen them as far as the toilet building)
