Update: After posting this earlier this afternoon, I got a twitter reply from USFWS Southeast:
@KF4LMT Good catch! We’re going to check with our experts and see if they know what this tag is for.
— US Fish and Wildlife (@USFWSSoutheast) August 18, 2014
This morning my father and I took a ride out to the Savannah NWR and it turned out to be an interesting visit. We’ve been long time visitors of the refuge and we something this morning that was a first for the both of us. We saw an alligator that had been tagged (photos below). I’ve seen a lot of alligators at the Savannah NWR but this one was the first I’ve ever seen tagged – it was what looked like a brass tag bolted through one of the ridges on the alligator’s back. I tweeted one of the photos to US Fish & Wildlife Southeast and am waiting for a reply to see if it’s any sort of special research or maybe how old it is.