'Eskimo' was a Canadian and US joint military exercise in the Canadian province of Saskatchewan, undertaken to test the Canadian army’s and USAAF’s current concepts of winter warfare (winter 1944/45).

Montreal Lake was a target area for dropping supplies by Boeing B-17 Flying Fortress and Boeing B-29 Superfortress four-engined heavy bombers to facilitate the operations of ground forces.

A suggested covert element of the undertaking was the dropping of an atom bomb by a B-29 and photographing the results for distribution to the Japanese government in an effort to spur it into ending the war. Chalk River, Ontario, was a research facility that contributed enriched uranium for the 'Manhattan' project, but great secrecy has cloaked the event ever since and efforts to uncover remnants in Montreal Lake have been thwarted by the area’s translation into a provincial park.