It connects the town of Unicoi with the community of Tiger Valley.

It goes eastward for several blocks before turning southward onto Unicoi Drive.

The merged SR 107/SR 173 goes eastward through rural mountain areas until reaching the community of Limestone Cove, where SR 107 turns southward toward the North Carolina border, and SR 173 turns northeastward through rural mountainous terrain to cross into Carter County and enter the community of Tiger Valley, where it comes to an end at US 19E.

From here, US 19E continues eastward to Roan Mountain, and northwestward to Hampton.

[1] Media related to Tennessee State Route 173 at Wikimedia Commons