US 421 Get started Zionville End Fort Fishero Length 325 mi Length 523 km Route Tennessee Boone Cricket Freeway River Street Wilkesboro Oakswoods Road North Wilkesboro Antioch Red White and Blue Road Clingman Ridgeview Road Cycle Brooks Crossroads Center Yadkinville East Yadkinville Shacktown Speer Bridge Road Dinkins Bottoms Road Shallowford Road Lewisville Lewisville Clemmons…