The Selk'nam, also known as the Onawo or Ona people, are an indigenous people in the Patagonian region of southern Argentina and Chile, including the Tierra del Fuego islands. They were one of the last native groups in South America to be encountered by migrant Europeans in the late 19th century. In the mid-19th century, there were about 4,000 Selk'nam; in 1916 Charles W. Furlong estimated there were about 800 Selk'nam living in Tierra del Fuego; with Walter Gardini stating that by 1919 there were 279, and by 1930 just over 100.

Beagle Channel is a strait in the Tierra del Fuego Archipelago, on the extreme southern tip of South America between Chile and Argentina. The channel separates the larger main island of Isla Grande de Tierra del Fuego from various smaller islands including the islands of Picton, Lennox and Nueva; Navarino; Hoste; Londonderry; and Stewart. The channel's eastern area forms part of the border between Chile and Argentina and the western area is entirely within Chile.