Calvin Gross is the Director of the Library, which means he is the ultimate boss of the library.
There are very few reasons that you will ever need to contact him directly. It is expected that you will usually go through the Chain of Command and approach your Labor Supervisor, Sienna Burgess, with questions/concerns first. If Sienna is unavailable, it is preferred that you next ask Amanda Peach, the Assistant Director and Head of Library Labor.
Here are some exceptions to that rule:
If someone wants to donate or gift books/materials to the library, you can refer them to Calvin. If the donation offer has come via email, just forward that email directly to him.
Calvin is scheduled for some evening shifts at the Reference Desk, so if you ever work from 6-9 pm, then at some point you may see him because of that.