[2] While the stream valley remains largely wooded, it has long been affected by nearby urban and suburban development, and its course has been followed for more than a century by railroads and rail trails.

[3] For the first hundred years after the founding of Washington, D.C., Coquelin Run drained "a patchwork of open fields around occasional farm houses and barns.

"[7] As the Civil War drew near, "by far the most prosperous Bethesda farmer" was "slaveholder Greenbury Watkins, a 52-year-old widower whose four young children were in the care of a hired governess.

[8] Suburban development reached Coquelin Run in 1892, when the Chevy Chase Land Company graded an extension of Connecticut Avenue from the District of Columbia to just north of the stream.

Where the tracks and the road ended, just past Coquelin Run's northern bank, the Land Company built a terminal complex: a railway office of pressed brick, a wood-framed car barn, and a coal-fired power house with a tall chimney.

[9] In 1910, the B&O extended its spur westward along upper Coquelin Run;[10] the following year, the Columbia Country Club built its golf course on both sides of about a quarter-mile of the stream.

[12][13] The proposal was opposed and ultimately defeated by local residents, civic groups, the Montgomery County Board of Education, and the Chevy Chase Land Company.

[11] In 2012, a planning report noted that invasive plant species had decreased the stream's natural biological diversity, and uncontrolled stormwater had eroded banks and deposited sediment that reduced habitat for aquatic animals.