One of the larger members of the Canadian Arctic Archipelago, Devon Island is the second-largest of the Queen Elizabeth Islands, Nunavut, Canada, the 27th largest island in the world and Canada's 6th largest island. The largest uninhabited island on Earth, Devon Island comprises of Precambrian gneiss and Paleozoic siltstones and shales. The highest point is the Devon Ice Cap at which is part of the Arctic Cordillera. Devon Island contains several small mountain ranges, such as the Treuter Mountains, Haddington Range and the Cunningham Mountains.
Because of its relatively high elevation and its extreme northern latitude, it supports only a meagre population of musk oxen and small birds and mammals; the island does support hypolith communities. Animal life is concentrated in the Truelove Lowland area of the island, which has a favourable microclimate and supports relatively lush Arctic vegetation. Temperatures during the brief (40 to 55 days) growing season seldom exceed 10 °C (50 °F), and in winter can plunge to as low as −50 °C (−58 °F). With a polar desert ecology, Devon Island receives very little precipitation.
Devon Island is also notable for the presence of the Haughton impact crater, created some 39 million years ago when a meteorite about 2 km (1.2 mi) in diameter crashed into what were then forests. The impact left a crater approximately 23 km (14 mi) in diameter, which was a lake for several million years.
The collapse of fur prices and the need to cut relief expenses led to the dispersal of 53 Baffin Island Inuit families on the island in 1934. It was considered a disaster due to wind conditions and the much colder climate, and the Inuit chose to leave in 1936. Dundas Harbour was populated again in the late 1940s to maintain a patrol presence, but it was closed again in 1951 due to ice difficulties.
Only the ruins of a few buildings remain at Dundas Harbour.
The Haughton crater is now considered one of Earth's best Mars analog sites. It is the summer home to a complementary scientific program, NASA's Haughton Mars Project. HMP has conducted geological, hydrological, botanical, and microbiological studies in this harsh environment since 1997. HMP-2008 is the twelfth field season at Devon Island.