You are about to enter the most scenic and rugged section of the Northwest Branch. This rocky gorge marks the "Fall Line," where the tough metamorphic rocks of the Piedmont, meaning "foot of the mountain," give way to the sandy sediments of the Coastal Plain. The rapid change in gradient creates a series of waterfalls, also referred to as the "Torrent and Gorge" section of the Northwest Branch. Below the Fall Line, the stream widens and slows down."Mother and I had a most lovely ride the other day, way up beyond Sligo Creek to what is called North-west Branch, at Burnt Mills, where is a beautiful gorge, deep and narrow, with great boulders and even cliffs.
Northwest Branch is a tributary of the Anacostia River. The rugged beauty of this area contributed significantly to the state of Maryland identifying the Anacostia as a "Scenic and Wild River" in 1984 under the Maryland Scenic and Wild Rivers Act.
On larger streams and rivers, the Fall Line generally marks the limit of travel by ships. Many large cities like Washington, D.C. and Baltimore were established just below this geographical barrier where ports could be established.
This spectacular, scenic, steep-sided stream valley was a favorite of President Theodore Roosevelt. President Roosevelt wrote of the area to his son:
Great Falls it is the most beautiful place around here. Mother scrambled among the cliffs in her riding habit, very pretty and most interesting. The roads were good and some of the scenery really beautiful.
We were gone four hours, half an hour being occupied with the scrambling in the gorge."
(The White House, June 21, 1904)
"Hearing can be a source of ...exquisite pleasure ... Take time to listen and talk about the voices of the earth and what they mean—the majestic voice of thunder, the winds, the sound of surf or flowing streams." — Rachel Carson, The Sense of Wonder (posthumously 1965)