In 1778 the Hudson's Bay Company engaged Philip Turnor as a surveyor to determine the positions of its posts. Although best remembered for his charting of the route to Athabasca (1790-92), and as the teacher of the geographers David Thompson and Peter Fidler, Turnor in fact spent most of his North American career as a trader and explorer on the Moose and Albany river systems (1780-87), and produced the first accurate maps of much of this part of northern Ontario. In 1792 he returned to London, where he ended his days as a teacher of navigation.