The Oakover River is formed by the junction of two creeks, Stag Arrow Creek and Bulldog Creek, on Balfour Downs pastoral station, and flows generally northwards about 275 kilometres to its confluence with the Nullagine River where these two watercourses combine to form the De Grey River.  Along the way it picks up the waters of the Davis River.

However, the hydrological length of the river, rather than its named length, extends south-west a further 42 kilometres along the course of the Stag Arrow Creek.

Frank Gregory named the Oakover River during his major North West Australia Exploring Expedition in 1861, probably after Samuel Moore’s property ‘Oakover’ on the Swan River, not far from the Gregory family residence.