Due to its hilly terrain and the relatively poor roads of 19th-century Sevier County, a number of smaller communities developed independently along the outskirts of Sevierville. These include Harrisburg and Fair Garden to the east and Catlettsburg and Boyd's Creek to the north. In addition, the United States Postal Service associates the name "Sevierville" with ZIP codes for much of Sevier County, including the town of Pittman Center and other geographically extensive areas located outside Sevierville's city limits.
