It continues northwest, takes in the right tributary Little Wabigoon River, then turns southwest back under the CP line and Highway 17 at the settlement of Taché.

The mercury entered the food chain and accumulated in fish which were a major part of the diet for First Nations people on reserves at Grassy Narrows and Whitedog.

This caused severe mercury poisoning with symptoms including neurological problems and birth defects among these people and also resulted in the closure of a commercial fishery and a fishing lodge in the area.

[3] In 1985, an agreement was signed which committed the federal and provincial governments and the two private companies involved to provide compensation.

Dissolved mercury is now low in the river system and past concentrations are recorded in the sediments of Clay Lake.