The Mountain extends from the Potomac River, in the north, to Manassas Gap, in the south. Along this section of the Blue Ridge Mountains, Blue Ridge Mountain comprises the sole ridge of the chain in the immediate vicinity and contains few spur ridges or peaks. The notable exceptions are the Bull Run and Catoctin mountains, which lie approximately to the east across the Loudoun Valley, and the Short Hill Mountain, located to the east, which runs parallel to the Blue Ridge for near its northern terminus. To the west of the mountain is the lower Shenandoah Valley.
Blue Ridge Mountain is noticeably lower in elevation than other sections of the Blue Ridge Mountains in Virginia. The southern section of the mountain contains the highest peaks and the ridge gradually loses elevation as it gets closer to the Potomac. Elevations in the gaps are typically around while peaks range from to . Across the Potomac the ridge continues as Elk Ridge in Maryland.