The Black River is a tributary of Lake Erie, about 12 mi (19 km) long, in northern Ohio in the United States. Via Lake Erie, the Niagara River and Lake Ontario, it is part of the watershed of the St. Lawrence River, which flows to the Atlantic Ocean. The Black drains an area of 470 mi² (1217 km²). According to the Geographic Names Information System, the Black River was formerly named "Canesadooharie River" and "Riviere en Grys." (These two historical names were actually originally intended to refer to nearby rivers, instead of the Black River.) Course The Black River is formed in the city of Elyria by the confluence of its east and west branches: The East Branch Black River is formed in northwestern Medina County by the confluence of two short tributaries, the East Fork Black River and the West Fork East Branch Black River. The East Fork flows southwardly past Lodi before turning northwestwardly, and the West Fork rises in northeastern Ashland County and flows generally eastwardly into Medina County; the two join about 1 mi (2 km) northwest of Lodi, and the East Branch then flows generally northwardly into Lorain County, past Grafton. It drains an area of 222 mi² (575 km²). The West Branch Black River, about 30 mi (48 km) long, rises in northern Ashland County and flows generally northeastwardly into Lorain County, past Rochester. It drains an area of 174 mi² (451 km²). From the confluence of the branches in Elyria, the Black River flows generally northwardly past Sheffield into the city of Lorain, where it enters Lake Erie at . The mouth of the river forms part of the harbor of Lorain. Name and history In the 1700s, the Black River was known as the "Reneshoua River", and was also referred to as "la Riviere de la Cuiliere" by early French and British explorers. The origin of those names is uncertain, although "Cuilliere" was also the name of a French fur-trader who frequented the Lake Erie shore areas about 1760. This river became well known by the early European explorers, as being the safest harboring spot at the western end of "the cliffs" which extended many miles along the southern Lake Erie shore from this river almost to the Cuyahoga River's mouth, and in the 1700s these cliffs had almost no beach areas for landing even a small boat, and were too high