The Allegheny, Susquehanna, Ohio, Delaware, Monongahela and Schuylkill are the principal rivers that run through Pennsylvania. Most have offshoots, called creeks or branches, that also run through the state. Other significant rivers in Pennsylvania include the Lackawanna, Lackawaxen, Juniata, Lehigh and Potomac. Minor rivers that run through Pennsylvania include the Christina, Little Schuylkill, Conestoga, Little Juniata, Cowanesque, Tioga, Mahoning, Shenango, Conemaugh, Little Conemaugh, Stoneycreek, Kiskiminetas, Clarion, Cheat and Beaver.
The Monongahela River, which originates in West Virginia, flows about 130 miles northerly toward Pittsburgh. There, it joins the Allegheny River to become the Ohio River. The Monongahela is used for barge commerce; steel, iron and coal are among the items that pass through its 106 miles of locks.
The Ohio River, which runs for 98 miles in Pennsylvania, originates at Pittsburgh as the combined body of water formed by the joining of the Allegheny and the Monongahela rivers. It flows northwest out of the state and ultimately into the Mississippi at Cairo, Illinois.
The Allegheny runs 321 miles north from Potter county in Pennsylvania to the New York State line, then southward toward Pittsburgh where it joins with the Monongahela to form the Ohio River.
The Delaware River originates in New York's Catskill Mountains and flows about 375 miles through Pennsylvania as well as New Jersey and Delaware. It has three main Pennsylvania tributaries: the Lackawaxen, the Lehigh and the Schuylkill. The Schuylkill has two branches, the East Branch (which begins in the Appalachians) and the West Branch (which begins at Minersville, Pennsylvania); the two branches merge at Schuylkill Haven). The Schuylkill runs through Pottsville, Reading, Norristown and to Philadelphia where it flows into the mouth of the Delaware.
The Susquehanna is America's 16th-largest river. It runs approximately 444 miles south and southeast from New York, entering Pennsylvania just north of Sayre and flowing through Scranton and Harrisburg and into Maryland where it empties into the Chesapeake Bay. Its tributaries include the Lackawanna, Chemung (an Iroquois word that means "horn in the water," so named because mammoth tusks were found in it) and Juniata rivers. Despite its length, the Susquehanna has never been a major commercial waterway because there are frequent obstructions along its route, including rapids.
