Tsimshian also speak the same language as the Gitxsan and the Nisga'a, yet the dialect is further differentiated than the regional Tsimshian variations.
From the en.wikipedia.org
More examples
A member of a Penutian people who lived on rivers and a sound in British Columbia
A Penutian language spoken by the Tsimshian
The Tsimshian (/u02C8su026Amu0283iu0259n/; Sm'algyax: Tsu2019msyan) are an indigenous people of the Pacific Northwest Coast. Their communities are mostly in coastal British Columbia and far southern Alaska, around Terrace and Prince Rupert in British Columbia, and Alaska's Annette Islands...