06. Blockhouse Point

Blockhouse Point Conservation Park features beautiful wooded bluffs and streams on the Maryland bank of the Potomac, 10 miles north of the Beltway, directly across the river from the Seneca Tract on the Virginia side. The park borders the Potomac River with near sheer bluffs forming a palisade that offer stunning views to the river and the Chesapeake and Ohio Canal.  Entirely forested, the park contains mature and generally undisturbed woods and numerous rock outcrops. Blockhouse Point Conservation Park is bordered on the east by Pennyfield Lock. On the west, Violette’s Lock is nearby. The Park extends north connecting to Muddy Branch Stream Valley Park. Along the Piedmont portion of the Potomac River, only the Gold Mine Tract of Great Falls National Park has a larger area of mature unfragmented forest.

Take River Road west from the Beltway. Look for a parking lot on the left, at a pipeline clearing, 6.5 miles west of the intersection with Falls Road (where the Muddy Branch Greenway Trail crosses), or a second parking lot 0.3 miles further up the hill on the left. You can also access the southwest corner of Blockhouse Point by turning off River Road onto Pennyfield Road. Park in the first parking lot on the right where there is a boat ramp on Muddy Branch, and follow a footpath alongside the C&O Canal that crosses a bridge over Muddy Branch and leads to a sewer access road, then look for the South Old River Road Trailhead on the left.

Directions and trail map. 

The view from Blockhouse Point over the C&O Canal and Towpath, looking across Seneca Breaks toward the Virginia side of the Potomac River:

The large contiguous forest south of River Road contains almost 400 acres of unfragmented forest, and supports forest interior species including barred owl, scarlet tanager, worm eating warbler, and ovenbird. This area provides ideal stop-over habitat for neotropical migrants that follow the river on their seasonal migrations. Bluffs overlooking the Potomac River offer premium high end avian real estate for nesting bald eagles as they continue to re-populate the area. Great Falls, not far downstream, has had a nesting pair for over ten years. 

The steep ravines above the canal and the upland forest throughout the natural area have particularly high quality forest dominated by white oak, chestnut oak, red oak, American beech and tuliptree. The lower forest areas include sycamore, red maple, river birch and slippery elm. Shagbark hickory and swamp chestnut oak, both largely uncommon in Montgomery County, occur within this area. The understory includes numerous native species such as pawpaw, lowbush blueberry, shadbush, and pinxter flower.  Many ferns and club mosses thrive on the lower slopes. Adjacent to the Potomac River, one can find several mountain species such as bladdernut, its seeds having traveled down river to find purchase on Piedmont soils along the river’s edge.

Bonus: you can put-in a canoe at Violette's Lock Road (turn left off River Road, one mile west of the upper parking area for Blockhouse Point), paddle across the Potomac River just above Seneca Breaks and enter the Patowmack Canal channel that starts at this point and hugs the Virginia bank in the Seneca Tract. Paddle back over to the Maryland side at the bottom of the 1-mile channel, pull your canoe up into the C&O Canal at the base of Blockhouse Point, and paddle back to your starting point on the flat water of the canal.