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Amid the bluffs that overlook the Potomac, Gulf Branch wends its way through the woods, gathering into a swimming hole for retrievers and hikers before spilling down a cliff and into the river. It’s too cold to swim now, but on a fall Saturday, the river is animated by sculls and kayaks, Latinos casting a line for tonight’s dinner, and couples manning Fletcher’s rowboats out to admire the fall foliage.

But the Virginia cliffs afford a better view—sunny, windblown, and momentarily quiet between the shouts of young recruits who rappel to the banks below.

The mile-and-a-half-long trail to the bluffs cuts back and forth over the stream that dribbles through makeshift dams assembled by children, then picks up speed as it sluices through increasingly massive rocks. In the summer, the trail is dark and cool. But now the maples, oaks, and tulip trees have surrendered their uppermost plumes, and the sun varnishes the leaves fallen to dapple the path and float down the creek.

Photosynthesis gives us life, but when chlorophyll diminishes and green transforms into a thousand different shades, nature gives us our biggest thrill. The trees put on an elaborate striptease, daring to bare their limbs as we bundle in sweaters to prepare for winter’s chill.

On the far bank, beyond the scrub and saplings stunted by seasonal floods, the beeches along the C&O Canal have already disrobed and their highest branches—unweathered and unsoiled, protected until now by their own canopy—glow beneath the hills mounting to the Palisades. The trunks float against the background of trees not so brazen; their forked boughs strangely resemble the inverted legs of giant herons.

Some six miles away, in soil nurtured not by the brackish eddies of the Potomac but by exhaust and the odd cigarette butt, are trees of another sort. Here in the grounds of the Inter-American Defense Board at 16th and Euclid Streets NW, are trees tinted by man, their trunks haphazardly dipped in white paint that has faded to gray. Outfitted in these doughboy knee socks, the trees stand at watch around the building, wearing their pale footwear long past Labor Day.

Has cable-access artist Bob Ross found a bigger canvas? A Washington City Paper T-shirt will be awarded to the person who offers the best explanation for the painted trees, and truly inspired answers will appear in next week’s edition if they reach us by Tuesday. Send your description, or suggestions of things that have been puzzling you, to: Mysteries, Washington City Paper, 2390 Champlain St. NW, Washington, DC 20009. Our fax number is (202) 462-8323, or e-mail us at MysteriesWashCP.com. No phone calls, please.