MACKENZIE, Sir Alexander, explorer, born in Inverness, Scotland, about 1755; died in Dalhousie, Scotland, 12 March, 1820. In his youth he emigrated to Canada, and became a clerk of one of the partners in the Northwest fur company. His employer determined to send him on an exploring expedition, but, before going, Mackenzie spent a year in England, studying astronomy and navigation. He then returned to Fort Chippewyan, on Lake Athabasca, where he had already spent eight years in trading with the Indians, and on 3 June, 1789, set out on his expedition, with four canoes and a party of twelve persons. At the western end of Great Slave lake he entered a river to which he gave his name, and explored it until 12 July, when he reached the Arctic ocean. Farther northward progress was stopped by ice. The farthest point that he reached was 69º north latitude. He then returned to the fort, where he at-rived on 27 September In October, 1792, he undertook. a more hazardous expedition to the western coast of North America and succeeded, in July, 1793, in reaching Cape Menzies, on the Pacific ocean, in latitude 52º 21' north, and longitude 128º 12' west, being the first white man to cross the Rocky mountains and reach the Pacific ocean. He returned to England in 1801 and was knighted the following year. He published a detailed account of his explorations, entitled "Voyages from Montreal, on the River St. Lawrence, through the Continent of North America to the Frozen and Pacific Oceans" (London, 1801).