The Back River rises on the Nunniong Plains, below Mount Bindi, that is part of the Great Dividing Range; in remote country east of Omeo.[3] The river flows generally east, then southeast, before reaching its confluence with the Timbarra River in a state forestry area, about 10 kilometres (6.2 mi) northeast of Ensay in the Shire of East Gippsland.[4][5] The river descends 588 metres (1,929 ft) over its 11 kilometres (6.8 mi) course.[2]