"Tasoo Harbour" adopted 7 March 1933, as listed in the 1930 Gazetteer of Canada. Name changed to "Tasu Sound" 3 July 1946 on Map 103SE. Tasu Sound confirmed 30 September 1946 on Chart #354.

Source: BC place name cards, files, correspondence and/or research by BC Chief Geographer/Geographical Names Office staff.

Identified as Tasso Harbour in Sailing Directions, Queen Charlotte Islands - Western Coast of North America, 1853, p.11; remarks by George H. Inskip, Master, RN. (British Library 10496.i.29). "Tasu" (pronounced Tass-soo) is a Haida word meaning "lake of plenty".

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

The sound, known as Tasoo (or Tassoo) Hbr in the early days, apparently takes its name from a longer Haida phrase meaning “lake of plenty.” Early US fur traders knew it as Port Montgomery after Maj Gen Richard Montgomery, an Irish native, who was killed in the unsuccessful US attack on Que in 1775. There were many Haida habitation sites on Tasu Sd, including the large winter village of Singa on Lomgon Bay; ancient trails connected the sound to Kootenay Inlet farther N and to Sewell Inlet on the E side of Moresby I. The first prospectors arrived at Tasu about 1907, and more trails were built, to Crescent Inlet and Lockeport to the SE. Falconbridge Nickel Mines Ltd established the Wesfrob iron-ore operation on Tasu Mtn in 1962 and built a modern townsite on Gowing I, complete with indoor swimming pool and gymnasium. More than 400 people lived at Tasu until the huge open-pit mine closed in 1983. In the 1970s the Canadian government allowed Russian fishing vessels to use Tasu Sd as a base in return for staying out of the Vancouver I fishing grounds (the crews were not allowed ashore). Tasu Ck, which flows into the head of Newcombe Inlet, takes its name from the sound.

Source: Scott, Andrew; "The Encyclopedia of Raincoast Place Names"; Harbour Publishing, Madeira Park, 2009, page 583.