Et-Then Island, Great Slave Lake

My attention has recently been drawn to an island in the Great Slave Lake, Northwest Territories, called “Et-Then Island”.

Does anyone know the origin of this name? There’s a geologic unit named after it, but I can’t find the meaning or origin of the name.

Here’s a map:

It’s named after a local native group.

On this page: there is a reference to “Etthen”

A Etthen Island Google book hit from the early 1800s(Royal Geographical Society) says it meant Rein-Deer Island, probably from the language of the Cree or the Chippewa.

Yeah, looks like it’s Dene (Chipewayan) for ‘Caribou’. Thanks!