Black Rock Mill – Pennyfield Lock loop from Twinbrook

Mountain biking trails

Black Rock Mill – Pennyfield Lock loop from Twinbrook

Hard

2.5

(21)

riders

Black Rock Mill – Pennyfield Lock loop from Twinbrook

08:57

115km

860m

Mountain biking

Hard mountain bike ride. Very good fitness required. Suitable for all skill levels. The starting point of the route is accessible with public transport.

Last updated: October 15, 2026

Tips

Cycling is not permitted along parts of this route

After 14.8 km for 220 m

After 18.9 km for 87 m

Waypoints

Start point

Train Station

Get Directions

23.1 km

Chesapeake and Ohio Canal

Lake

27.6 km

Widewater

Lake

29.3 km

Viewpoint

29.6 km

Start of the Great Falls Foot Trail

Highlight • Trail

The Great Falls of the Potomac is a place with various rapids and small falls in the Potomac. The place marked here may only be entered on foot. Bicycles and dogs 😜 must stay outside.

Translated by Google •

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39.5 km

Bridge over Muddy Branch near Riley’s Lock

Highlight • Bridge

This is a very picturesque area, with the bridge, the creek, and the house up the hill beyond the field.

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41.3 km

Blockhouse Point Conservation Park

Nature Reserve

48.0 km

Muddy Branch Stream Trail

Highlight (Segment) • Trail

A beautiful natural surface trail that gently rolls along the Muddy Branch Stream for nine miles.

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61.5 km

Seneca Creek State Park

Nature Reserve

63.1 km

Black Rock Mill

Highlight • Historical Site

Just the walls remain of the 1815 Black Rock saw- and gristmill in Seneca Creek State Park. The structure was stabilized and representations of mill machinery were added in 1980.

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71.0 km

Dry Seneca Creek Stream Crossing

Highlight • River

Crossing Dry Seneca Creek on stepping stones.

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76.7 km

Riley’s lock

Highlight • Monument

Riley’s Lock is a fun, happening place. Every time I pass by it is bustling with activity. There are two row boat clubs along Seneca creek. There are kayak, jet …

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81.8 km

Lock 22, aka Pennyfield Lock, was built between 1829 and 1831, and the name came from the misspelling of the Pennifield family name. It has been restored and offers overnight stays to recreate the rustic feeling from that period.

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