Seeking the Northwest Passage and the fabled like to Russia, Japan, and Cathay, Alexander Mackenzie drove himself and his men relentlessly, by canoe and portage, across the uncharted rivers, valleys, and mountains of North America. Mackenzie's 1789 journey to the Arctic Ocean and his arduous journey to the Pacific in 1793 predate the Lewis and Clark expedition. By the age of thirty-one Alexander Mackenzie had become the first man to cross North...