Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
Kwalhioqua–Clatskanie (Kwalhioqua–Tlatskanai, Lower Columbia Athabaskan) is an extinctAthabaskan language of northwest Oregon and southwest Washington state, along the lower Columbia River. It was documented in the early 20th century, and a wordlist was compiled, consisting of some 322 words.
Dialects
Dialects were:
Kwalhioqua (a.k.a. Willapa or Willoopah) (north of the lower Columbia River)
Willapa or Wela'pakote'li subdialect
Suwal subdialect
Clatskanie (a.k.a. Tlatskanai) (south of the lower Columbia River)