The Mahoning River is a river in northeastern Ohio and a small portion of western Pennsylvania. Flowing primarily through several Ohio counties, it crosses the state line into Pennsylvania before joining with the Shenango River to form the Beaver River. The Mahoning River drops from 1,296 feet (395 m) at the headwaters near Winona to 761 feet (232 m) at the outfall near Mahoningtown, Pennsylvania. It is part of the Ohio River watershed. The name is said to derive from either the Lenape or Shawnee languages and mean "Deer Lick," as the area was once known for salt springs, but it's possible the name of the Mahoning and several other similarly named landmarks and places in western Pennsylvania could come from the Lenape, mënehokink (may-nuh-ho-keeng), meaning "place to get water."

The Shenango River is a principal tributary of the Beaver River, approximately 100 mi (160 km) long, in western Pennsylvania in the United States. It also briefly flows through small portions of northeastern Ohio. Via the Beaver and Ohio Rivers, it is part of the watershed of the Mississippi River.