The Susquehanna River cuts through the folds of the Valley-and-Ridge province of the Appalachian Mountains in this photograph taken by the crew of the International Space Station.
The Valley-and-Ridge province is a section of the larger Appalachian Mountain Belt between the Appalachian Plateau and the Blue Ridge physiographic provinces. The northeast-southwest trending ridges are composed of Early Paleozoic sedimentary rocks. The valleys between them were made of softer rocks (limestone and shales) that were more susceptible to erosion; they are now occupied by farms. The Susquehanna River cuts through several ridges as it flows south.
The Susquehanna River flows 444 mi (714 kilometers) from upstate New York to Maryland, draining into Chesapeake Bay.NASA