Cellular towers--regardless of their location--should have a full aeronautical analysis conducted and must have FAA approval before construction. Any tower that will have a transmitter must have FAA approval. Any company that wants to co-locate on a site will require a study and filing for FAA approval. Should you wish to sell your tower in the future to another company, having a complete study and FAA in hand will make for a smoother transaction.
If you plan to co-locate on a standing tower, you will want to see the aeronautical study, the FAA's "Determination of No Hazard" and FCC Registration on the existing site. Never consider co-location without this valuable information.
