The
Susquehanna River is a
river in the northeastern
United States. At approximately 410
mi (715
km) long, it is the longest river on the American East Coast. The Susquehanna forms from two main branches, with the North Branch, which rises in upstate
New York often regarded as an extension of the main branch. The shorter
West Branch, which rises in western
Pennsylvania, is sometimes regarded as the principal tributary, joining the Norrth Branch near
Sunbury in central Pennsylvania. The river drains a large watershed within the
Allegheny Plateau of the
Appalachian Mountains, cutting through
water gaps in the lateral mountain ridges in a broad zigzag course to flow across the rural heartland of southeastern Pennsylvania, emptying in the north end of the
Chesapeake Bay.