Prince William Forest Park · VA
South Valley Trail
The park's longest trail, following the South Fork of Quantico Creek past small cascades and rocky sections through hardwood forest; part of it carries the Potomac Heritage National Scenic Trail.
Live · updated
Today
Skip the trail running plan today.
Today's best: trail running
Conditions
Score by activity
Hiking
Skip the hiking plan today.
Trail running
Skip the trail running plan today.
Score breakdown
- − 88°F air — Above trail running's comfort zone (28–78°F)
- − Thunderstorms — Get off exposed ridges before they arrive
- ✓ Trail: prime — No meaningful rain in the last 48 hours. Trail surface is dry and tacky — prime traction.
- − 80 min of daylight — You need at least 133 min with margin. Bring a headlamp or start tomorrow.
Trail facts
- Distance
- 7.4 mi
- Elevation gain
- 976 ft
- Surface
- dirt
- Difficulty
- moderate
Trailhead
Coordinates
38.5816, -77.4114 — VA.
Park
Part of Prince William Forest Park (official site →).
Peak nymphal tick activity — check yourself within 2 hours of leaving the trail.
Frequently Asked
How long is South Valley Trail?
South Valley Trail is a 7.4-mile route with 976 feet of elevation gain — moderate — some sustained climbing or technical sections; expect to work for it but no specialized skills required. The trail facts panel on this page lists distance, surface, and access tags as they appear in OpenStreetMap.
What's the trail surface like at South Valley Trail?
South Valley Trail is natural dirt singletrack — soft underfoot, holds water, slow to dry after rain. Today's mud rating, derived from recent precipitation and the surface type, is shown in the conditions panel above.
Who manages South Valley Trail, and where do closure alerts come from?
South Valley Trail is in Prince William Forest Park, which is managed by the National Park Service. Closure and advisory data on this page comes from the live NPS alerts API for this park unit. Always confirm against the park's own page before driving — emergency closures can post faster than scrapers refresh.