Length: 5.5 miles, one way
The Balcony Falls Trail [FS 7], a portion of which some maps and guidebooks identify as an extension of the Sulphur Spring Trail, gradually descends for 5.5 miles, passing a couple of views of the James River, to reach VA RT 782.
An automobile can reach this trailhead by following FSR 35 (which becomes VA RT 781) from Petites Gap (BRP mile 71.1) for 3 miles to VA RT 759. (Along the way pass trailheads for the Sulphur Spring Trail [FS 7; same as Balcony Falls Trail], 1 mile from the BRP, and the Belfast Creek Trail [FS 9], 2 miles from the BRP.)
Turn right onto VA RT 759 and follow it for 3 miles to VA RT 782. (About 1.5 miles from the junction of VA RT 781 and VA RT 759 is the Gunter Ridge Trailhead [FS 8], .3 mile beyond the Glenwood Iron Furnace.
A right turn onto VA RT 782 for another 1.5 miles will bring you to the Balcony Falls Trailhead [FS 7]. The trail begins 17.4 miles into the Sulphur Springs Trail and ends at the 22 mile mark.
17.4 Trail intersection. The Appalachian Trail makes a hard left and continues to ascend.
The Belfast Creek Trail [FS 9] goes right for .4 mile to an intersection with the Gunter Ridge Trail [FS 8] then bears left for 1.5 miles to Devils Marbleyard, a large area of giant boulders. It then descends Belfast Creek for another mile to VA RT 781. (See trailhead directions in the mile point 16.9 description above.)
The Gunter Ridge Trail [FS 8] bears right from the intersection and uses switchbacks through a profuse growth of mountain laurel to reach VA RT 781 in 4.5 miles. (These trailhead directions may also be found in the mile point 16.9 description above.)
19.2 Trail intersection. Cross to continue to gradually ascend on the AT.
To the left, the Sulphur Spring Trail [FS 7] descends 2 miles to the AT and Balcony Falls Trail [FS 7] intersection (mile point 16.9). To the right, the Sulphur Spring Trail passes the Piney Ridge Trail [FS 2] in 1.5 miles and continues to follow the old road an other 2.5 miles to Sulphur Spring and FSR 35. (See the mile point 16.9 description above for trailhead directions.)
The Piney Ridge Trail [FS 2] bears left from the Sulphur Spring Trail to gradually descend the ridge line for 3.5 miles to FSR 54. This trailhead may be reached by leaving the BRP at mile 63.7, following US RT 501 west for .5 mile, and turning left onto FSR 54. The trail begins about a half mile up this road.
19.8 Marble Spring campsite. The spring is .1 mile to the right. Continue on the AT with ascents, steeply at times.
20.7 Attain Highcock Knob (no views) and descend quickly.
21.9 Arrive at Petites Gap and FSR 35. The BRP (mile 71.1) is less than 500 feet to the left.