[4] The Tsimshianic languages were included by Edward Sapir in his Penutian hypothesis, which is currently not widely accepted, at least in its full form.

The Penutian connections of Tsimshianic have been reevaluated by Marie-Lucie Tarpent, who finds the idea probable,[5] though others hold that the Tsimshianic family is not closely related to any other North American language.

Southern Tsimshian was spoken on an island quite far south of the Skeena River in the village of Klemtu; however, it became extinct in 2013 with the death of the last speaker.

Gitksan is spoken along the Upper Skeena River around Hazelton and other areas.

Nisga’a and Gitksan are very closely related and are usually considered dialects of the same language by linguists.