In 1903, McMartin established himself in Cornwall, Ontario, where he was president of the Labrador Pulp and Paper Company and of the Motherlode Sheep Creek Mining Company, and vice-president of Hollinger Consolidated Mines.
McMartin established himself in Cornwall, Ontario. This was in 1903. He was president of the Labrador Pulp and Paper Company and of the Motherlode Sheep Creek Mining Company. He was president of vice-president of Hollinger Consolidated Mines.