Furnace Mountain, Jones Run, and Austin Mountain Loop

This is a 17.6-mile loop from the Madison Run boundary access through Furnace Mountain, Blackrock, Jones Run, Doyles River, Big Run, Rockytop and Austin Mountain. The two-day itinerary covers 8.8 miles each day and is rated for experienced hikers; budget about 15 hours of hiking across both days, apart from breaks and the overnight. The published total includes the optional one-mile round-trip Furnace Mountain summit spur. Skip that out-and-back and plan about 16.6 miles. This is a backcountry route with steep, rocky climbs and stream crossings, not a set of short waterfall walks.

From the boundary gate, walk about 0.1 mile up Madison Run Fire Road to Furnace Mountain Trail. The climb crosses Madison Run on stones, follows the creek briefly, then gains the ridge over rocky ground and a boulder field. A one-mile round-trip spur reaches Furnace Mountain's summit outcrop, with views toward Massanutten and a glimpse of Skyline Drive. Continue on Trayfoot Mountain Trail, take Blackrock Spur, and climb onto the broad talus at Blackrock Summit. The open boulders give the circuit its broadest panorama across the valley and surrounding ridges; watch your footing on the uneven rock.

From Blackrock, the route takes the Appalachian Trail north before dropping down Jones Run to the confluence with Doyles River. Jones Run Falls, a 42-foot drop, is the main waterfall stop here. Turn upstream on Doyles River Trail to pass two more falls, bringing the route's total to three. These streamside miles are beautiful but can slow the day: crossings on Jones Run may become difficult or dangerous in spring and after heavy rain, and Doyles has crossings as well. If water is high, do not treat a marked crossing as automatically safe.

At the Appalachian Trail, turn south, then take Big Run Loop to its four-way junction. Stay straight onto Rockytop rather than continuing around Big Run Loop; turn onto Austin Mountain Trail at the next junction. The ridge offers occasional looks back toward Furnace Mountain. Austin's lower descent is the roughest finish: a long stretch of loose talus leads to a steep drop to Madison Run Fire Road. Looking uphill, the slanted rock wall has a castle-like outline. The final 0.7 mile on the fire road returns to the boundary gate.

Quartzite underlies many of the South District's cliffs and boulder fields, and freeze-thaw weathering helps break the rock into the talus you cross at Blackrock and Austin. Furnace Mountain takes its name from Mount Vernon Furnace, an iron-smelting site at its base; its exact construction date is disputed, so the date is best left out. The Madison Run corridor can also be a good place to listen for spring and early-summer songbirds, including warblers and Louisiana waterthrushes.

Start at Madison Run Boundary on Browns Gap Road (Virginia Route 663), near Route 708. The roadside parking area holds about eight cars; keep the gate clear. Bring a route map and know the junction order, especially where Big Run Loop meets Rockytop. There is no verified restroom, food service or potable water at the access. A Shenandoah entrance pass is required even when entering on foot from the boundary. The two-day plan involves backcountry camping, which requires a purchased permit. Pets are allowed on this route, but must stay on a physical leash no longer than six feet.