Just north of the bridge, the state highway's surface changes from asphalt to gravel. The gravel road continues for about  on the state highway's crossing of Clinch Mountain. SR 91 returns to asphalt road just south of its intersection with SR 604 (Thompson Valley Road), from which the highway follows Maiden Spring Road.
The state highway changes from asphalt to gravel near a bridge, continuing for a distance on the highway's crossing of Clinch Mountain. SR 91 returns to asphalt just south of its intersection with SR 604 (Thompson Valley Road), and then follows Maiden Spring Road.