 At the Washington–Scott county line, US 421 and US 58 veer northwest again and follow a curvaceous path through Shelly Ridge and Cove Ridge, after which the highways follow Cove Creek southwest through the valley of the North Fork Holston River until the highways turn northwest, cross the river, and pass through Hilton Gap in Pine Ridge.The highways pass through the village of Hiltons and parallel the Appalachia Division rail line southwest through the Poor Valley to the town of Weber City, where the highways meet the northern end of SR 224 (Wadlow Gap Road), cross Moccasin Creek, and intersect US 23 (Main Street).US 421, US 23, and US 58 run concurrently with the Appalachia Division rail line through Moccasin Gap, where Moccasin Creek passes through Clinch Mountain.