It also briefly flows through small portions of northeastern Ohio.

The Shenango, whose name comes from the Iroquoian "Shanango," meaning "the beautiful one," rises in west-central Crawford County[6] and initially flows northwestwardly into the Pymatuning Reservoir, which was formed in 1934 by the construction of a dam on the river.

[8] The lake turns to the south, widening into Ashtabula County, Ohio, and passing through Pymatuning State Park.

[7] Below the dam and after returning fully to Pennsylvania, the Shenango flows south-southeastwardly into Mercer County, flowing through Jamestown and Greenville before turning westwardly into Shenango River Lake,[7] formed in 1965 by a United States Army Corps of Engineers dam.

[9] Below that dam, the Shenango flows southwestwardly through the communities of Sharpsville and Sharon (near which it briefly enters Trumbull County, Ohio); then south-southeastwardly past Farrell, Wheatland and West Middlesex into Lawrence County, where it passes New Castle and Oakland.