Adopted 3 April 1934 on C.327, as labelled on British Admiralty Chart #584, 1863 et seq.

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

The Huu-ay-aht spelling for Tsusiat Falls is Tsosayii-aht or Cuusayii-aht, meaning "waterfall split in two by a rock". This is the southeast boundary of Huu-ay-aht traditional territory. "Tliishin's land reached the waterfall (Cuusayii-aht) on one side and on the other side went as far as Coleman Creek /Yashitquo-a." (Huu-ay-aht Place Names in the Chief Louie Nookemus historial accounts, c1964, shared September 2009 in the context of the Maa-nulth First Nations Treaty.) "My grandfather's domain reached Tsosayii-aht." (also from the Chief Louie Nookemus historical accounts, c1964)

Source: included with note

The name "Tsusiat" with the map notation "remarkable water fall" on British Admiralty Chart 584, published in 1863 from 1861 from surveys by Captain Richards, RN.

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

According to BC historians Helen and Phillip Akrigg, Tsusiat is a Ditidaht First Nation word meaning “water pouring down” – ie, a waterfall. The Tsusiat River pours over a wide ledge directly onto the beach and into the ocean, making spectacular Tsusiat Falls one of the most photographed and popular campsites on the West Coast Trail. Tsusiat Lake takes its name from the river and falls. A dramatic sea arch at Tsusiat Point, called Hole in the Wall, has given nearby feature an alternative local name: Hole Point.

Source: Scott, Andrew; "The Encyclopedia of Raincoast Place Names"; Harbour Publishing, Madeira Park, 2009, page 606.