Summer Trail Days In North Potomac: The 9-Mile Backyard Most Neighbors Haven't Walked End To End

If you live off Darnestown Road or anywhere between Quince Orchard and River Road, there is a nine-mile trail that starts about as close to your driveway as the grocery store, and most of your neighbors have only ever walked a quarter mile of it. They know the trailhead near their subdivision. They have not connected the dots south.

That is the thing worth fixing this summer. North Potomac does not just border a few parks. It sits at the top of a stitched-together corridor that runs from Darnestown Road all the way down to the C&O Canal at Pennyfield Lock, and the connective tissue is the Muddy Branch Greenway Trail.

The Connector Most Residents Miss

Muddy Branch Stream Valley Park, Blockhouse Point Conservation Park, and the C&O Canal Towpath tend to get talked about as three separate destinations. They are not. According to Montgomery Parks, the Muddy Branch Greenway runs nine miles of natural-surface trail from Darnestown Road down through the stream valley, past the Potomac Horse Center, and into Blockhouse Point, where a bridge now lets walkers and cyclists cross over to Pennyfield Lock on the towpath.

That bridge is the piece that changes how you use the trail. Before it, the greenway ended in a shrug at the canal edge. Now the greenway is a true through-route, and the loop possibilities open up: down the greenway, out onto the flat towpath, back up through Blockhouse Point's bluff trails. The North Potomac Citizens Association calls the greenway the county's newest multi-use natural-surface trail, and it is genuinely accessible to most walkers without being flat or dull.

The Three Parks, Side By Side

Locals lump these together as "the trails behind us." They are not the same experience.

The rule that trips people up: within Blockhouse Point, biking is prohibited on every trail except the Muddy Branch Greenway segment that skirts the eastern edge. If you have watched a neighbor pedal into the woods off River Road and wondered whether that was allowed, Montgomery Parks' trail page is clear: hiking only on the interior trails, hiker or equestrian on the rest, bikes on the greenway.

A Saturday Route From Your Driveway

Here is a real loop that uses all three, sized for a summer morning before it gets hot:

1. Park at the small lot on Pennyfield Lock Road, on the right where the boat ramp sits on Muddy Branch. This is the southern trailhead and the least crowded of the access points.
2. Cross the footbridge over Muddy Branch. On the far side, pick up the South Old River Road trailhead into Blockhouse Point.
3. Climb to the bluff overlooks. Two viewpoints sit roughly 80 feet above the Potomac and the canal, and even in July when the trees are full, the sight lines to the river hold up. This is where the Union blockhouses stood during the Civil War, watching for Confederate raiders across the Potomac. Confederate troops burned the camps in 1864, and interpretive signage near the parking area on River Road walks through the archaeology.
4. Loop back down the Paw Paw Trail or the horse trail through the National Park Service land.
5. Return along the C&O Canal towpath. The stretch between Violette's Lock and Pennyfield Lock is famously flat, well shaded, and rich in birdlife: red-tailed hawks, kingfishers, and blue herons work this section, and there are port-a-johns at both locks.

AllTrails clocks the full Blockhouse Point Loop at seven miles with 442 feet of elevation gain, which puts it firmly in the "moderate before breakfast" bracket. If you want the shorter version, the greenway-to-towpath out-and-back from Pennyfield gives you a two-mile taste of the same corridor.

Small Things Worth Knowing

A few specifics that separate people who live here from people who Google-mapped in:

• Parking is small on purpose. Two modest lots sit on the south side of River Road for Blockhouse Point, and the Pennyfield Lock lot fills fast on Saturday mornings after nine. Show up by 8:30 in July, or plan a weekday walk.
• Tobytown is next door. The Pennyfield Lock access sits near Tobytown, a historic African American community founded in 1875 by formerly enslaved families. It is a piece of Montgomery County history that gets skipped over on most trail descriptions.
• The Potomac Horse Center sits on the greenway. If you have kids who like animals, the greenway threads past the horse center between Darnestown Road and River Road. It is a real working equestrian facility, not a petting zoo, so keep dogs leashed and stay on the trail.
• Dogs are welcome, on-leash. Seneca Creek State Park, Muddy Branch Stream Valley Park, and the C&O Towpath all permit leashed dogs. The towpath crushed stone is easier on paws than the natural surface trails after a dry stretch when the dirt gets sharp.
• The greenway takes rain hard. The Seneca Greenway signage warns that sections close after heavy rain, and Muddy Branch behaves the same way. Give it 48 hours after a summer thunderstorm before you commit to a long day.

What About When You Want More Than Nine Miles

If the greenway is your baseline and you are looking to stretch, the next tier north is Seneca Creek State Park, where the Schaeffer Farm trail system is a mountain-biking favorite and the paved loop around Lake Inspiration in Gaithersburg is wheelchair and stroller accessible. To the south, the towpath keeps going in both directions for as long as your legs hold up: eight miles west gets you to the shade of Seneca Aqueduct, six miles east delivers you to Great Falls Tavern.

For a real project, the Seneca Ridge, Seneca Greenway, and Seneca Bluff Trail Loop is a 26-plus-mile day out that AllTrails logs at about 1,824 feet of ascent. That is not a summer-morning walk. It is a training goal for the fall.

Why This Matters More Than It Sounds

The reason to know your trail network well is not really about exercise. It is about what North Potomac is. The stretch of Montgomery County between Route 28 and the Potomac was preserved on purpose, and the greenway is the payoff for decades of that preservation work. Blockhouse Point alone contains almost 400 acres of unfragmented forest and supports interior species like barred owl, scarlet tanager, and ovenbird according to the trail description compiled by local naturalists. That kind of habitat does not survive by accident in a county this densely built.

Neighbors who use these trails weekly tend to be the ones who talk about North Potomac as a place, not a zip code. If you have lived here a while and only ever walked the first half-mile from your local entrance, this is the summer to walk the whole thing end to end. Bring water. Start early. See where the bridge takes you.

If you love the corner of Montgomery County you already call home and want a neighbor's perspective on what makes it worth staying invested in, Valerie Harnois writes about North Potomac the way a resident would, not a brochure. Let's connect when you're ready to talk about your next chapter here.