The Cyriac river valley is directly served by the route 175; other secondary forest roads have been developed in the sector for forestry and recreational tourism activities.

[1][2] Forestry is the primary economic activity in the sector; recreational tourism, second.

The north mouth of Pikauba Lake is located at: From Pikauba Lake, the course of the Cyriac river generally flows northwest over 57.2 km (35.5 mi), with a drop of 663 m (2,175 ft) entirely in the forest zone, according to following segments: Upper course of the Cyriac river (segment of 23.0 km (14.3 mi)) Lower course of the Cyriac river (segment of 34.2 km (21.3 mi)) The Cyriac river flows on the south shore of Lake Kénogami, facing Île Verte and facing Baie Voisine de l'Île à Jean-Guy.

This confluence is located at: From the confluence of the Cyriac river with Kenogami Lake, the current crosses this lake for 6.3 km (3.9 mi) northeast to the dam of Portage-des-Roches, then follows the course of the Chicoutimi river on 26.2 km (16.3 mi) to the east, then the northeast and the course of the Saguenay river on 114.6 km (71.2 mi) east to Tadoussac where it merges with the Saint Lawrence estuary.

[3] The toponym "Cyriac River" was formalized on December 5, 1968, at the Place Names Bank of the Commission de toponymie du Québec.