With your gallery having a height of 100%, it will fill its parent container (no matter what its size) so to reduce the gallery's height, you will need to reduce the height of the parent container or set a height for the parent container if it does not already have one. If setting the gallery's height to 100%, Juicebox needs to know what it should be 100% of.
Otherwise, try giving your gallery a fixed pixel height such as 600px or a smaller percentage height.
When using percentage heights, it may be necessary to use inline CSS to assign heights to parent containers.
Please see this note for Using Percentage Heights.
I swear I tried this multiple times and all it would do is give me a ~400px vertical blank space and no gallery. When I entered it again after your suggestion it did the same, then I refreshed it 3 or 4 times and then the gallery suddenly loaded as I wanted it. Weird stuff, but it works now. Thanks for your time.
Cole