Downstream of Youngstown, Ohio through Struthers and Lowellville in Ohio and Edinburg in Pennsylvania, the river runs through a significant valley. In contrast and notwithstanding some shallow reservoirs and short waterfalls, the river upstream of there flowing through Newton Falls and Warren encounters less relief in the ground and the terrain is largely flat right up to the riverbank. Therefore, the term "Mahoning Valley" is generally applied locally only to the lower portion of the drainage unless addressing the Youngstown–Warren, OH-PA Combined Statistical Area which is also often referred to colloquially as the "Mahoning Valley" for the purposes of referring to issues such as job opportunities and housing markets.
