The portion of US 50 from Parkersburg, West Virginia to Winchester, Virginia follows the historic Northwestern Turnpike, which crosses the southern tip of Garrett County, Maryland. From Parkersburg to Interstate 79 east of Clarksburg, US 50 has been upgraded as part of the four-lane divided Corridor D. US 50 is a curving two-lane mountain road, east of Clarksburg through Grafton, a bit of Maryland, and Romney to Winchester. This portion of the road is so curvy that locals claim you can meet yourself coming. The land flattens out after the route crosses the Blue Ridge Mountain east of Winchester, and it follows the old Little River Turnpike from Aldie to Fairfax City and the newer Arlington Boulevard to Rosslyn, where it crosses the District of Columbia line on the west shore of the Potomac River and joins Interstate 66 on the Theodore Roosevelt Bridge.