From its source in the central White Mountains near the Paths of The Dead, the River Morthond acted as the boundary between Gondor's provinces of Anfalas and Lamedon. The Morthond had one tributary, the River Calenhir, which flowed from the eastern slopes of the Pinnath Gelin.

The River Morthond ultimately joined the river Ringló and flowed into Copas Haven at the site of the ancient Elf-Haven and Port of Edhellond.