The Appalachian Trail Conservancy and its maintaining clubs must pay for ridgerunners, so they only assign them during peak times when the tidal wave of thru-hikers will roll through. For GSMNP, this means mid-March through the end of June. The heaviest mix of hikers (early season thru-hikers and spring breakers) hit in March. It's all about the money per hiker ratio.

But my advice to stick to an itinerary still stands. I saw a couple who had to backtrack a couple of miles when they decided to bypass the shelter on their itinerary in '08. It's best to stick with the schedule.