The rivière aux Trembles (English: Aspen River) is a tributary of Pémonca River, flowing in the unorganized territory of Lac-Ashuapmushuan, in the Le Domaine-du-Roy Regional County Municipality, in the administrative region of Saguenay–Lac-Saint-Jean, in the province from Quebec, to Canada.

The Trembles river valley is mainly served by forest roads.

[1] The Trembles river has its source at the mouth of a small lake (altitude: 440 m (1,440 ft)).

This source is located in a forest area in the municipality of La Doré, at: From its source, the Trembles river flows on 23.4 km (14.5 mi) with a drop of 168 m (551 ft), especially in agricultural and village areas at the end of the route, depending on the segments following: The Rivière aux Trembles pours into the bottom of a narrow bay to the south-east of Lac à la Truite, which turns out to be one of the two head lakes of the Pémonca river.

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