The Collin River originates at the mouth of an unidentified lake (length: 2.0 kilometres (1.2 mi) formed in length in the North-South axis with a narrowing of the shoreline in the center of the lake; 461 metres (1,512 ft)).

The mouth of this head lake is located at 3.6 kilometres (2.2 mi) south-east of R0807 which runs northward to the west of Martin Lake; at 18.1 kilometres (11.2 mi) north of the confluence of the Collin River with the Mégiscane River; at 35.0 kilometres (21.7 mi) east of downtown Senneterre; and at 37.4 kilometres (23.2 mi) south-east of the mouth of Parent Lake (Abitibi).

The main hydrographic slopes near the Collin River are:

• North side: Lake Mayor-Bilodeau;
• East side: Doyon Lake, Bastien River, Faillon Lake, Mégiscane River;
• South side: Mégiscane River;
• West side: Martin Lake, Signay Creek, Sunday Creek, Brassier River, Parent Lake (Abitibi).

From its source, the Collin River flows over 22.1 kilometres (13.7 mi) according to the following segments:

• 4.0 kilometres (2.5 mi) southerly, crossing a first unidentified lake (length: altitude: 458 metres (1,503 ft)) and a second lake, to its mouth;
• 2.5 kilometres (1.6 mi) south across Regis Lake (length: 1.3 kilometres (0.81 mi); altitude: 425 metres (1,394 ft)) on its full length, up to at its mouth;
• 3.2 kilometres (2.0 mi) to the south, in particular, crossing an unidentified lake (length: 0.7 kilometres (0.43 mi); altitude: 417 metres (1,368 ft)), up to mouth of a second unidentified lake;
• 1.9 kilometres (1.2 mi) south to the outlet of Délisle Lake (coming from the North-East);
• 1.7 kilometres (1.1 mi) south to the outlet of Lamarche Lake (coming from the Northeast);
• 3.4 kilometres (2.1 mi) south to R0806 (Penetration Road);
• 5.4 kilometres (3.4 mi) south to confluence

The Collin River discharges on the north shore of the Mégiscane River (elevation: 340 metres (1,120 ft)) which flows southwest and then northwest to Parent Lake (Abitibi) which empties into the Bell River, a tributary of 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 Collin River with the Mégiscane River flows to:

• 3.36 kilometres (2.09 mi) south-west of the mouth of Faillon Lake;
• 53.3 kilometres (33.1 mi) south-east of the mouth of Parent Lake (Abitibi);
• 35.2 kilometres (21.9 mi) south-east of the confluence of the Mégiscane River with Parent Lake (Abitibi);
• 1.8 kilometres (1.1 mi) north-east of the Canadian National Railway; the nearest rail stop being "Press";
• 36.9 kilometres (22.9 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