<Tr> <Th_colspan="2"> Basin features </Th> </Tr> <Tr> <Th> Basin size </Th> <Td> 2,932 km (1,132 sq mi) </Td> </Tr> <P> The Mahoning River is a river located in eastern Ohio and western Pennsylvania . Flowing primarily through several Ohio counties, it joins the Shenango River to form the Beaver River and is part of the Ohio River watershed . </P> <Table> <Tr> <Td> </Td> <Td> This section does not cite any sources . Please help improve this section by adding citations to reliable sources . Unsourced material may be challenged and removed . (July 2012) (Learn how and when to remove this template message) </Td> </Tr> </Table>

Where does the mahoning river start and finish