The Buckhannon River is formed at the community of Alexander in southern Upshur County by the confluence of the Left Fork Buckhannon River and the Right Fork Buckhannon River, both of which rise in southwestern Randolph County at elevations of and , respectively, and flow generally north-northwestwardly into southern Upshur County. The Right Fork flows through the communities of Pickens and Selbyville and collects tributaries known as the Middle Fork Right Fork Buckhannon River and the Left Fork Right Fork Buckhannon River; the Left Fork of the Right Fork flows through the community of Helvetia.