 Between Yorktown and Fredericksburg, the U.S. Highway serves as the primary highway of the Middle Peninsula.At Fredericksburg, US 17 leaves the Atlantic coastal plain; the highway passes through the Piedmont town of Warrenton and crosses the Blue Ridge Mountains on its way to Winchester in the Shenandoah Valley.The route from Tappahannock to Winchester roughly follows the Confederate March during the Civil War to Gettysburg.US 17 enters Virginia at the North Carolina state line adjacent to the Dismal Swamp Canal in a rural area east of Great Dismal Swamp National Wildlife Refuge and northwest of Elizabeth City.