US 340 and US 522 head north along four-lane divided Winchester Road. The highways pass through Cedarville, the site of the Virginia Inland Port, and through Nineveh, the site of the historic estate Erin. North of Nineveh, the routes follow the Warren–Frederick county line and enter Clarke County, where the road is named Stonewall Jackson Highway. US 340 and US 522 diverge at a four-legged intersection at Double Tollgate, from which US 522 continues north toward Winchester; the west leg of the junction is SR 277 (Fairfax Pike), which heads toward Stephens City. US 340 heads east along two-lane Lord Fairfax Highway. The highway passes north of Greenway Court and veers north at White Post, the site of the Greenway Historic District and the White Post Historic District. US 340 intersects US 17 and US 50 (Millwood Pike) at Waterloo and passes through the town of Boyce and its eponymous historic district, surrounding which are three historic plantations: Huntingdon, Saratoga, and Scaleby. The highway crosses Page Brook and parallels the Hagerstown District rail line through the Chapel Rural Historic District, which is centered around the namesake old chapel at the route's junction with SR 255 (Bishop Meade Road) at Briggs. US 340 continues to the town of Berryville, through which the route follows Buckmarsh Street. The U.S. Highway intersects SR 7 Bus. (Main Street) within the Berryville Historic District, which contains the Old Clarke County Courthouse.