Plummers Island

Plummers Island is a 12-acre Potomac River island in Montgomery County, Maryland, about nine miles upriver from Washington, D.C., which holds the distinction of being the most scientifically studied island in North America. It is visible from the American Legion Memorial Bridge of the Capital Beltway, just downriver of the bridge.
Scientific study of Plummers Island began in 1899, when botanist Charles Louis Pollard formed the Washington Biologists' Field Club and began the search for a field camp near the club's Washington, D.C. home. The club leased the island in 1901, and bought it seven years later; the island is now owned by the U.S. National Park Service.

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