Shuckstack from Twentymile is a 10.6 mile out and back trail located near Tallassee, TN that features a great forest setting and is rated as moderate. The trail is primarily used for hiking and is accessible year-round.
This is a great hike! A nice forest hike next to the river for the first three miles, followed by a pretty intense climb to the AT after the Long Hungry Ridge junction. Once you get to the AT junction and turn south towards Fontana, it's just another 1/3 of a mile uphill to the Shuckstack summit tower. Absolutely with it on a clear day!
Also, they have recently replaced the stairs on the tower itself, so its not as precarious as other reviews suggest. - I would also advise bringing a bug net for the sections along the river if you are hiking in spring/summer.
This hike was quite strenuous on the way up, almost 3 solid miles of uphill, but the way down it was 5 miles downhill, so the way back was pretty easy. I would considerate it a moderate hike altogether. It was well worth it for a 360° view of the Smokies from the Fire Tower! Be sure to go on a clear day because you will be amazed!!