This plate shows the depths (bathymetry) of the waters in and around Northern Canada, together with the relief (orography) of the land as it was known in 1957. The bathymetric information was supplied by the Canadian Hydrographic Service; the orographic information by the Topographical Survey; and the names of the principal physical features by the Geographical Branch, Department of Mines and Technical Surveys [now Natural Resources Canada]. All isolines and elevations are in feet.