Existed: 1933 – present Constructed 1933 | Length 69.8 km | |
Counties Johnson County, Tennessee, Sullivan County, Tennessee | ||
U.S. Route 421 is a north–south United States highway that runs for 43.4 miles (69.8 km) in East Tennessee, connecting the cities of Mountain City and Bristol.
Route description
US-421 enters Tennessee just north of Zionville, North Carolina, going in a northwesterly direction to, the oldest unincorporated community in the state, Trade. Connecting with SR-67 (hidden concurrency), it soon forms the eastern boundary of the Cherokee National Forest at the intersection of Bulldog Road; then completely in the National Forest after passing Old Prison Camp Road.
In Mountain City, SR-67 splits-off, going southwest towards Elizabethton; SR-91 soon joins afterwards (hidden concurrency). Soon afterwards, US-421 makes traverses through the Iron Mountains, where the road becomes aggressively curvy with elevation changes throughout; at Sandy Gap, US-421 will reach the highest point of its route in Tennessee at 3,862 feet (1,177 m). Once descended from the Iron Mountains, US-421 goes through Shady Valley, where SR-91 splits-off in on a southwesterly direction towards Elizabethton. Soon the highway climbs up Holston Mountain, entering Sullivan County, from Johnson County at Low Gap. This is the second stretch of aggressively curvy with constant elevation changing along US-421, which continues until it reaches Holston Valley, located west of Holston Lake. This whole section, between Mountain City and Holston Valley, is very popular with cycle enthusiasts.
US-421 is joined with SR-44 (hidden concurrency) at Holston Valley, where travelers can make their first chance towards Interstate 81 in Abingdon, Virginia. At Vinegar Hill, US-421 widens to a divided four-lane highway; soon afterwards SR-44 splits-off, continuing southwesterly direction to Bluff City.
Entering Bristol city limits at the intersection of SR-394 and SR-435, the highway reverts to a two-lane road, as it goes through the Fairmount Neighborhood. Near the state line, US-421 connects to Martin Luther King Jr. Boulevard via Andrew Street, before heading north into Virginia.
The entire route is overlapped with SR-34, which was mostly hidden throughout.