Mac Addresses

Does anyone know how I can trace a mac addresses or have any suggestion to the following?

I have a copy of bridges that connect two of my buildings. They are set up so only the two talk to each other. On the inside of the remote building, I have a couple of users. When I check to see what MAC addresses are trying to attach, I find a list of them. I also have several other wireless point around the campus, but on the two bridges talk to each other. I want to find out who the other mac addresses belong too so I can block them from even trying to connect. Suggestions?