Eastern Continental Divide

A map of the principal hydrological divides of North America. The Eastern Continental Divide (orange line) demarcates two watersheds of the Atlantic Ocean: the Gulf of Mexico watershed and the Atlantic Seaboard watershed.

The Eastern Continental Divide, in conjunction with other continental divides of North America, demarcates two watersheds of the Atlantic Ocean: the Gulf of Mexico watershed and the Atlantic Seaboard watershed. Prior to 1760, the divide represented the boundary between British and French colonial possessions in North America. The ECD runs south-southwest from the Eastern Triple Divide in Pennsylvania to the watershed of the Kissimmee River, which drains via Lake Okeechobee and the Okeechobee Waterway to both the Gulf of Mexico and the Atlantic Ocean.

The geography for the 1763 demarcation line separating the Thirteen Colonies from lands west of it generally runs along, or close to, the Eastern Continental Divide's line going from the southern Georgia border northwards to the existing Pennsylvania/New York state border, and from there northeastwards along the St. Lawrence Divide into New England.

Because the divide represents the highest terrain, air is forced upwards regardless of wind direction. This process of orographic enhancement leads to higher precipitation than surrounding areas. In winter, the divide is often much snowier than surrounding areas, due to orographic enhancement and cooler temperatures with elevation. Some locations in North Carolina average up to 100 inches (2,500 mm) of snow a year, and up to 175 inches (4,400 mm) a year falls in parts of West Virginia.

Red Creek west of the crest of the Allegheny Front in the Dolly Sods area of West Virginia; the creek originates along the Eastern Continental Divide, with its waters flowing to the Gulf of Mexico as part of the Ohio River watershed.

Seneca Creek, incised into the Allegheny Front west of Seneca Rocks, West Virginia. This short but steep creek originates along the Eastern Continental Divide; its waters flow into the Atlantic Ocean via the Potomac River and Chesapeake Bay.

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