 After passing through the Devil's Racepath, US 58 and US 421 split from US 23 as Daniel Boone Trail just south of the town of Duffield.US 23 passes through the town, where the highway parallels the Appalachia Division rail line and the North Fork Clinch River through a gap between Powell Mountain and Cliff Mountain.The U.S. highway briefly enters Lee County while following the river between Powell Mountain and Walden Ridge to its source at Wildcat Summit at the Lee–Wise county line.