Georgia doesn't require one. Neither does Tennessee, or either of the Carolinas. I do believe Florida requires one for some areas. When I was in Florida back in June, the original plan was to drive from one side of the Everglades to the other all offroad, but when I called the office to inquire if they had any maps they could send me ahead of time to pre-map a route, they told me that a pass was required, and an entire vehicle inspection had to be performed at one of their approved centers. I had never heard of anything like that before.
In fact, it was a three step process. First you had to obtain an Operator Permit which requires taking an online course, and then filling something out, and then presenting it to the Offroad Office down there. Secondly, you have to have a vehicle inspection. They check for things like tread depth and how loud your exhaust is. Then thirdly, you have to get the annual vehicle permit. It's a process that can only be done in person (with the exception of the online course) on Friday, Saturday, and Sunday from 12:30-4:00PM. Needless to say they don't make it easy.