The Middle Prong of Little River drains the watershed between Miry Ridge and Defeat Ridge, both of which descend from the crest of the Smokies. The Middle Prong is formed by the confluence of Lynn Camp Prong and Thunderhead Prong at the former logging town of Tremont, where it has cut a deep gorge. From here, the river continues northward, absorbing Spruce Flats Branch and several smaller streams before steadying in a relatively flat area known as Walker Valley. The Middle Prong is shadowed by the old roadbed of the Little River Railroad for almost all of its nine-mile (14 km) length.