US-803377, sent by Renae. Renae also has a postcard blog: www.thelaptoptraveler.blogspot.com
On the back of the card: "Autumns colors reach their peak October 15-31 in the Smokies. By mid-September the foliage starts to change in the northern hardwood forest above 4500 feet before spreading into the hardwoods in lower elevations. Reds generally are red maple, pin cherry and mountain ash; yellows are American beech, yellow birch and yellow buckeye."