The Bastien River rises at the mouth of an unidentified lake (length: 0.4 kilometres (0.25 mi) altitude: 452 metres (1,483 ft)) on the southern flank of a mountain. An assembly summit (northwest of the lake) reaches 513 metres (1,683 ft).

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 main hydrographic slopes near the Bastien River are:

• North side: Lac Valets, Delestres River, Lalochetière Lake;
• East side: Wilbrod Lake, Faillon Lake, Mégiscane River;
• South side: Faillon Lake, Mégiscane River;
• West side: Collin River (Mégiscane River tributary), Martin Lake.

From its source, the Bastien River flows on 17.2 kilometres (10.7 mi) according to the following segments:

• 4.9 kilometres (3.0 mi) towards the North-East between the mountains, to the bottom of a bay on the southwestern shore of Bastien Lake;
• 1.7 kilometres (1.1 mi) north-east across Bastien Lake (length: 1.9 kilometres (1.2 mi); altitude: 455 metres (1,493 ft)), up to mouth;
• 1.9 kilometres (1.2 mi) north-east across an unidentified lake (length: 1.2 kilometres (0.75 mi); altitude: 415 metres (1,362 ft)), up to its mouth.

This segment of river passes on the South side of a mountain whose highest peak reaches 530 metres (1,740 ft);

• 0.8 kilometres (0.50 mi) northeasterly to the outlet (from the northwest) of Henri and Abel lakes;
• 3.4 kilometres (2.1 mi) north-east, then south-east skirting a mountain whose summit reaches 411 metres (1,348 ft), to the dump (coming from the North-East) Ubald and Ducheneau lakes;
• 4.5 kilometres (2.8 mi) south to confluence^[2]

The Bastien River is discharged on the north shore of Faillon Lake which is crossed to the southwest by the Mégiscane River (elevation: 355 metres (1,165 ft)). From this confluence, it flows southwest and then northwest to Parent Lake (Abitibi), which empties into the Bell River, a tributary of the Matagami Lake. The latter lake in turn flows into the Nottaway River, a tributary of the southeastern shore of James Bay.

This confluence of the Bastien River with the Mégiscane River flows to:

• 9.8 kilometres (6.1 mi) north-east of the mouth of Faillon Lake;
• 39.3 kilometres (24.4 mi) east of the confluence of the Mégiscane River with Parent Lake (Abitibi);
• 50.1 kilometres (31.1 mi) south-east of the mouth of Parent Lake (Abitibi);
• 13.1 kilometres (8.1 mi) north of the Canadian National Railway; the busiest rail stops being "Press" and "Paradise";
• 44.9 kilometres (27.9 mi) east of the village center of Senneterre.

• Nottaway River, a watercourse
• Matagami Lake, a body of water
• Bell River, a watercourse
• Parent Lake (Abitibi), a body of water
• Mégiscane River, a watercourse
• Senneterre, a city
• La Vallée-de-l'Or Regional County Municipality (RCM)
• List of rivers of Quebec