For our fall trips we often go to the Cherokee or Brevard, North Carolina areas.  Both are rich with terrific rivers and streams and a short drive from Atlanta.  We try to schedule a trip that is just on the back side of fall leaf watching.  This way, we avoid the crowds and most of the troubles with leaves.  There is just a nip in the air and the fish are looking for food.  Louisa has a nice rainbow in the Cherokee area.