… Matachewan and Mattagami First Nations in their commitment … – which represents five First Nations, including Matachewan and Mattagami … and member First Nations outlines how the First Nations will … the project,” Mattagami First Nation Chief Chad Boissoneau …… Matachewan and Mattagami First Nations in their commitment … – which represents five First Nations, including Matachewan and Mattagami … and member First Nations outlines how the First Nations will … the project,” Mattagami First Nation Chief Chad Boissoneau …