The Bastien River flows into the town of Senneterre in La Vallée-de-l'Or Regional County Municipality (RCM), in the administrative region of Abitibi-Témiscamingue, in Quebec, Canada.

The course of the river successively crosses the townships of Martin, Valets and Faillon.

The Bastien River flows entirely in forest territory, generally towards the South.

The mouth of this head lake is located at 4.5 kilometres (2.8 mi) north-west of the R0808 forest road, which runs north-east along the north shore of the Mégiscane River; at 7.0 kilometres (4.3 mi) north of the confluence of the Bastien River with the Mégiscane River; to 38.5 kilometres (23.9 mi) north-east of downtown Senneterre; and at 44.0 kilometres (27.3 mi) south-east of the mouth of Parent Lake (Abitibi).

The latter lake in turn flows into the Nottaway River, a tributary of the southeastern shore of James Bay.