The road is very curvy as it does go through a mountainous area.

Its northern terminus is U.S. Route 19E (US 19E) in the town of Roan Mountain and its southern terminus is North Carolina Highway 261 (NC 261).

SR 143 begins at the top of Roan Mountain on the North Carolina border, where it continues south as North Carolina Highway 261.

SR 143 then enters the town of Roan Mountain and intersects with its former alignment through town before bypassing downtown to the west before coming to an end at an intersection with US 19E/SR 37.

The entire route is in Carter County.