The Valley Railroad was constructed on the west side of Massanutten Mountain,
while the original Shenandoah Valley Railroad was built through the Page Valley
(and ultimately merged with the Norfolk and Western)
Source: Library of Congress -
Map showing lines and connections of the Shenandoah Valley and Norfolk & Western Railways (1881)
The modern Shenandoah Valley Railroad connects Pleasant Valley (south of Harrisonburg) and Staunton. It is a "short line" railroad, dedicated to moving local traffic from industries in the valley to connect with the Norfolk Southern at the north end or the CSX in Staunton.
Today's Shenandoah Valley Railroad is a former part of the Valley Railroad, developed after the Civil War. It was financed in part by the B&O, while a rival line called the Shenandoah Valley Railroad was financed initially by the Pennsylvania Railroad. The Valley Railroad was built between Harrisonburg and Lexington, connecting on the north ultimately to the B&O at Harpers Ferry. The Valley Railroad plans to connect Lexington to Roanoke were never built, in large part because the original Shenandoah Valley Railroad was completed first.