Adopted 6 April 1950 on 92/NW, as labelled on British Admiralty Chart #1917, 1849 et seq, and on BC Lands' map 2C, 1919, and as listed in the 1930 BC Gazetteer.

Source: BC place name cards, or correspondence to/from BC's Chief Geographer or BC Geographical Names Office

"Estero is the Spanish word for "lagoon", and was first applied to the inlet known now as Frederick Arm, by Galiano & Valdes during their expedition of 1792. The Spaniards evidently first explored this inlet (even though Vancouver may have earlier passed by it), and found the lagoon or basin at the end of it, consequently naming the whole "Ensenada del Estero" ("Bay of the Lagoon)". This is the name which appears on the Spanish chart of 1795 resulting from the voyage." (copy of anaylsis by Wagner, including translation of Galiano's journal 23 July 1792, received August 1971, file B.3.51).

Source: Provincial Archives of BC "Place Names File" compiled 1945-1950 by A.G. Harvey from various sources, with subsequent additions