The Beaver River is a tributary of the Ohio River in Western Pennsylvania in the United States with a length of approximately 21 mi (34 km). It flows through a historically important coal-producing region north of Pittsburgh. The Beaver River is formed in Lawrence County by the confluence of the Mahoning and Shenango rivers at a point approximately 3 mi (5 km) southwest of New Castle. It flows generally south, past West Pittsburg and Homewood. It receives Connoquenessing Creek west of Ellwood City and flows past Beaver Falls and New Brighton. It joins the Ohio at Beaver and Rochester (flowing between these two towns) at the downstream end of a sharp bend in the Ohio approximately 20 mi (32 km) northwest of (and downstream from) Pittsburgh. In the lower reaches near the Ohio River, the Beaver cuts through a gorge of underlying sandstone.