U.S. Route 421 (US 421) traverses approximately 328 miles (528 km) across North Carolina; from Fort Fisher, on Pleasure Island between the Atlantic Ocean and Cape Fear River, to the Tennessee state line near the community of Zionville. The highway is nominally labeled "north" and "south" throughout North Carolina, though it really follows a general northwest-southeast path, and the segment from Greensboro to Boone is almost due east-west, with compass west corresponding to the signed north direction.