US 23, US 58, and US 421 receive their three business routes at an interchange west of Gate City. The U.S. Highways parallel the railroad and Little Moccasin Creek west between Clinch Mountain to the south and Moccasin Ridge to the north. The highways curve north and parallel the Clinch River to Clinchport, where the road meets the southern end of SR 65 and begins to follow Stock Creek. US 23, US 58, and US 421 pass by Glenita, where the railroad splits north to pass through the Natural Tunnel, the centerpiece of Natural Tunnel State Park. 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.