Linden sits astride the Warren and Fauquier county lines, SR 55 (the John Marshall Highway) and Interstate Highway 66. At above sea level, it sits at the top of the Manassas Gap in the Blue Ridge Mountains making it a gateway into the Shenandoah Valley today, as it was for early settlers in the area. The Manassas Gap Railroad was completed in 1854, it ran through Linden from Mount Jackson to Manassas Junction giving the town of Manassas its name. Today the tracks form a part of the Norfolk Southern rail system. The popular north-south Appalachian Trail crosses Hwy 55 (John Marshall Hwy) and under I-66 in Linden at County Rd 725 (Tuckers Ln.) as it follows its way along the east side of the Blue Ridge.