At the very end of this road, near the Duplanter spillway, is the former worksite of the Société d'énergie de la Baie-James, named Caniapiscau.

Prior to impoundment, Lake Caniapiscau covered about 470 square kilometres (180 sq mi) and was frequented by hunters and fur traders in the 19th century.

It now fills a depression in the highest part of the Laurentian Plateau of the Canadian Shield, covering 4,318 square kilometres (1,667 sq mi), or about four times the size of the natural lakes prior to impoundment.

The area surrounding the reservoir is vegetated entirely with taiga, or boreal forest, characterized by widely spaced Black Spruce with a thick underlayer of yellow-grey lichen and interspersed with muskeg and bogs.

On the more exposed land, a forest-tundra transition zone occurs where the woodland is replaced by lichen dominated tundra.