Black River-Matheson is a township in the Cochrane District of the Canadian province of Ontario.

[2] Mining, forestry and farming are some of the principal industries in the area, augmented by outdoor tourism in the summer, such as fishing and hunting.

The communities in the township are Holtyre, Matheson, Ramore, Shillington, Val Gagné, and Wavell.

McDermott found a gold-bearing zone in 1922, which became American Barrick's Holt-McDermott Mine in 1988.

Located in the Abitibi greenstone belt, the mine produced 60,000 ounces of gold in 1994.