"There is one significant change to the marked trail that is not yet reflected in all trails."
That line comes from a hiker who posted a trail review this month, not long after Scott's Run Nature Preserve reopened. If you've been waiting since February to get back on the Outer Loop, the preserve is open again. What you'll find when you get there isn't quite the trail you left.
Scott's Run, off Georgetown Pike at the edge of McLean, closed on February 16, 2026 for what Fairfax County called an urgent repair to the siphon system that carries the county's wastewater under the Potomac River. The closure covered both parking areas and every trail in the preserve, and it lasted through the summer. The county's public works department confirmed the sewer work itself wrapped up August 10, with the park reopening on August 21 once maintenance crews finished cleaning up after months of construction traffic on the trails.
That's six months, not the three the county originally estimated when the closure was announced. Anyone who hikes here regularly already knows this wasn't the first time. It's worth understanding why, because the two closures were not the same project, and knowing the difference tells you something about how solid this reopening actually is.
Two Different Closures, Two Different Problems
In March 2024, Fairfax County shut Scott's Run down on an emergency basis after an inspection found that two of the preserve's three wastewater siphon pipes were no longer operational. Those pipes carry sewage from McLean across the Potomac, through Carderock National Park in Maryland, and into D.C. Water's Potomac Interceptor. With only one working pipe left and no backup route, the county brought in specialized equipment from out of state to clean and patch the system before it failed outright. That closure was planned for about six weeks, and the follow-up cleanup work continued until valve work wrapped up in January 2025.
This year's closure was different. It wasn't a patch job, it was the actual fix. Crews relined 1,200 linear feet of the siphon facility using cured-in-place pipe lining, essentially rebuilding the interior of all three pipes rather than just clearing a blockage. That's why it took longer and why the county frames it as a rehabilitation project rather than an emergency response. The upside for anyone who hikes here: this was designed to be the repair that holds, not another stopgap that reopens the same conversation in another year or two.
One more detail worth knowing before you plan a return visit. This was Phase 1. Phase 2 of the same project, which will handle the section of pipe running under the river itself into Carderock National Park, is still in the design stage, with construction anticipated for fall 2027. The county's project page notes that phase will likely require closing a small portion of Carderock on the Maryland side, with limited impact expected on the Virginia side. Scott's Run itself isn't expected to close again for that phase. For now, the preserve is fully back in rotation.
The whole project, for what it's worth, is funded through sewer service charges and connection fees rather than general tax revenue, according to the county's own project documentation.
What's Actually Different on the Ground
The preserve keeps its familiar shape. Two entrances sit off Georgetown Pike (State Route 193), each with a small parking lot. The first lot, right off the road, sits closer to Scott's Run itself, the stream that gives the preserve its name and that starts its life in the Tysons Corner shopping district before winding through this valley to the Potomac. The second lot, a short drive further west, is the main entrance and the one most hikers use to reach the bluffs above the river.
From there, the trail network hasn't been redrawn, but at least one junction has moved. The recent trail review flagged a marked change on the reopened trail that hadn't yet made it into mapping apps. If you're navigating from memory or an old screenshot rather than checking signage on the day, budget extra time at unfamiliar-looking junctions rather than assuming the fork you remember is still where you left it.
The trail itself still runs the route regulars know: past the Scott's Run Waterfall, east along the Potomac on a stretch thick with roots and exposed rock, then inland through a residential edge before picking up a connector to the Oak Trail. From there a left turn onto the Stubblefield Falls Overlook Trail drops you back toward the smaller parking lot, with a final connector trail closing the loop. The Potomac Heritage National Scenic Trail also runs blazed through the preserve, maintained in part by the Potomac Heritage Trail Association, so if you're stitching together a longer hike toward Great Falls or back toward Turkey Run, the markers are there to follow.
A few things haven't changed and are worth repeating for anyone new to the preserve or returning after a long break:
- Dogs are welcome but must stay leashed
- Swimming and picnicking aren't permitted anywhere in the preserve, and the county enforces this strictly given how quickly the Potomac's current can turn dangerous near the falls
- Parking is limited at both lots, so an early start matters more here than at most Fairfax County parks
- The terrain shifts from gentle forest paths to steep, rocky descents depending on which loop you take, so this isn't a stroller-friendly park end to end
Why Fall Is a Good Time to Go Back
The timing of this reopening lines up well with the season. Scott's Run sits within a stretch of mature hardwood forest, mostly tulip poplar and American beech, with an unusually open lower canopy that makes it easier to spot birds moving through than in denser woods nearby. The Virginia Department of Wildlife Resources lists it as a stop on the state's Bird and Wildlife Trail specifically because migrants pass through in high numbers each fall, on top of the summer and scarlet tanagers and several warbler species that breed here. If you've hiked Scott's Run mainly for the spring wildflowers, the trailing arbutus and Virginia bluebells that carpet the hillsides, fall is a quieter but genuinely good reason to come back.
The preserve's grove of ancient hemlocks, holdovers from a colder climate that once reached this far south, is also easiest to appreciate once summer crowds thin out. None of that changed in the six months the park was closed. What changed is that the risk hanging over every visit, the possibility that the county would need to come back and shut the trails down again for the same underlying pipe problem, is largely resolved for the McLean side of the project.
If you're heading back for the first time since February, treat the reopening the way the trail review suggested: assume one turn isn't where it used to be, and give yourself a minute at the junctions before committing to a direction.
We track changes like this across McLean because they're part of what it actually feels like to live here day to day, not because they show up in a listing description. If you've walked the new stretch of trail and noticed something else that hasn't hit the map yet, we'd genuinely like to hear about it. Reach out to TSR Homes any time you want to compare notes on what's changing around McLean, on the trails or off them.
