It took me a while to dig up this information so I wanted to create this note to help others find it. Apparently directories are mapped to drive letters on Windows using the "subst" command. So if you want to find out what directory a mapped drive letter is pointing at, open a DOS "cmd" window and type "subst".
Of course this is not the same as viewing network mapped drives. Oh no, let's not try to confusing people by using the same command for two completely different things (read sarcasm here). To view network mappings type the command "net use".
It seems totally bizarre that you can't get the mapping information for a directory mapping from the mapped drive properties dialog. Network drive mappings show up right in the top level windows explorer view of your computer. Ah well, such is the love/hate relationship with Windows.