Geophysical and geomorphic mapping was undertaken to better understand the evolution and sedimentary history and geomorphology of two lake basins in the Yukon Territory of the Western Canadian Arctic. Lake Herschel is a relatively young (Holocene) lake found in the centre of Herschel Island, an island in the Southern Beaufort Sea which is composed of permafrost and thick ice-rich sediments. Trout Lake" is located at the foothills of the British Mountains in a zone of thin cryotic and thin generally ice-poor sediments overlying bedrock along the northern Yukon Slope and likely formed during the Pleistocene. This is the first time that either lake has been mapped using geophysical methods. A Mala Ground Penetrating Radar (GPR) system with a 50MHz and 100 MHz antenna was used to map the lake basins and surrounding stratigraphy. The system was pulled along the surface of the frozen lakes in a grid of transects. Positioning control for the GPR data was collected with a GPS system. Validation data for depth control was provided by a number of holes drilled in the ice for water depth. Piston cores were obtained to characterize the sub-lake floor sediments.