The best way to get to Bird Island is to start at the Public Beach Access located at West 40th Street on Sunset Beach NC. Take the access to the beach, and head Southwest (away from the pier). You can either walk or ride a bike, it is about 1.5 miles from the 40th Street access to The Kindred Spirit Mailbox.
The Mailbox is a little hidden but look for the flag pole with the American flag, it’s visible from the beach. If you reach the jetty you’ve gone a little too far.