| Selden Island | |
| Pushpin Map: | Maryland |
| Pushpin Map Caption: | Selden Island (Maryland) |
| Coordinates: | 39.0753°N -77.4528°W |
| Location: | Potomac River |
| Area Acre: | 408 |
| Length Km: | 4.0 |
| Width Min Km: | 0.3 |
| Width Max Km: | 0.5 |
| Elevation M: | 65 |
| Country: | United States |
| Country Admin Divisions Title: | State |
| Country Admin Divisions: | Maryland |
| Country Admin Divisions Title 1: | County |
| Country Admin Divisions 1: | Montgomery |
| Population: | 0 |
| Population As Of: | 2022 |
Selden Island is a 408-acre island in the Potomac River, located about 32km (20miles) WNW of Washington, DC. It is about 4 km long and 0.4–0.5 km wide (2.5 x 1/4–1/3 miles). Although it is located within Montgomery County, Maryland, the only road access is via a bridge connecting it to the Loudoun County, Virginia side of the river.
Archaeological evidence indicates the island has been a site of human activity since the Early Woodland period, around 1000 BC. A characteristic type of pottery known as Selden Island ware dates from this period.[1] It is also the site of a significant Late Woodland period settlement known as the Walker Prehistoric Village, which was added to the National Register of Historic Places in 1975.[2]
In 2002, following the diagnosis of two Loudoun County teenagers with malaria, mosquitoes from the island were found to carry the Plasmodium vivax malarial parasite.[3]
In 2004, Selden Island was purchased by the Howard Hughes Medical Institute as an addition to the Janelia Farm Research Campus.[4] It was formerly leased as a sod farm.