| SR 28 in Whitwell|| 99.3 km|
| SR 55 Bus. / SR 56 / SR 380 in McMinnville|
Altamont, Gruetli-Laager, McMinnville, Whitwell, Coalmont, Palmer, Viola
Marion County, Tennessee, Grundy County, Tennessee, Warren County, Tennessee
State Route 108 (SR 108) is a 61.7-mile-long (99.3 km) state highway in Southeastern and Eastern Middle Tennessee. It connects Tennessee State Route 28 in Whitwell to Tennessee State Route 55 Business/Tennessee State Route 56/Tennessee State Route 380 in McMinnville.
Tennessee State Route 108 Wikipedia
SR 108 begins at an intersection with Tennessee State Route 28 in Whitwell. It travels to the north as Main Street and then turns northeast as Cumberland Drive and leaves the Whitwell city limits. It then ascends to the top of the Cumberland Plateau and passes through primarily rural terrain until it reaches Grundy County, where it enters the town of Palmer and passes through its downtown area. Then, it continues on a northerly track until it leaves Palmer's town limits.
Just before it has an intersection with SR 399, the highway turns west and enters the city of Gruetli-Laager and passes through the city's main area. After approximately 6 miles (9.7 km), SR 108 enters the city of Coalmont and has an intersection with SR 56 for the first time. Approximately 1 mile (1.6 km) past the SR 56 intersection, it leaves Coalmont and enters rural terrain again, where it comes to SR 50 and turns back north on SR 50 east. After approximately three miles (4.8 km), the two routes enter Altamont's city limits. After another three miles (4.8 km), they intersect SR 56, and travel concurrently for approximately 184 feet (56 m). This intersection also serves as the eastern terminus for SR 50. SR 108 then leaves SR 56 and turns back west. After approximately four miles (6.4 km), it leaves Altamont. Just after leaving Altamont, it turns back north and continues on a northerly track until it intersects SR 127 just south of the town of Viola.
SR 108 and SR 127 stay merged for eight miles (13 km) to an intersection where SR 108 turns north and SR 127 continues northeast. SR 108 enters the McMinnville city limits and continues north until it intersects SR 55 Business. It then travels concurrently with SR 55 Bus. and goes northeast to its northern terminus with SR 56 and SR 380.