Across the Monongahela River to the west, Rostraver runs adjacent with six Washington County neighborhoods, including (from north to south): Carroll Township, Donora, another segment of Carroll Township, Fallowfield Township, North Charleroi, Charleroi, and Speers (connected by the Belle Vernon Bridge on I-70).
acrOss THe moNONgaHeLa rIveR TO tHe weSt, ROStraVeR RuNs aDjacEnT wiTH siX washIngTon CoUNty NeiGhBorhoods, iNCluDinG (from North to south): carroll TOWNsHip, donOra, AnothER seGmeNt OF carroll TownsHiP, falLoWfieLd townsHIp, nOrTh CHARlERoI, chaRleroi aNd SpeeRs (connecTed bY the belLe veRnon BRidGe on i-70).