Allegheny CountyThis dataset contains locations of major rivers that flow through Allegheny County. These shapes have been taken from the Hydrology dataset. The Ohio River, Monongahela River and Allegheny River are coded as Major Rivers.allegheny-county-major-riversengWestern Pennsylvania Regional Data Center Open DataPublicEnvironmentGeographyAllegheny County Major RiversDatasetsPennsylvania--Allegheny CountyPennsylvaniaLast Modified: 2026-02-21