Kathlamet was a Chinookan language that was spoken around the border of Washington and Oregon by the Kathlamet people. The most extensive records of the language were made by Franz Boas, and a grammar was documented in the dissertation of Dell Hymes. It became extinct in the 1930s and there is little text left of it.
Kathlamet was spoken in northwestern Oregon along the south bank of the lower Columbia River. It has been classified as a dialect of Upper Chinook, or as Lower Chinook, but was mutually intelligible with neither.
- Franz Boas, Kathlamet Texts. Bulletin of the Bureau of American Ethnology No. 26. Washington, DC: U.S. Government Printing Office, 1901.
- Dell H. Hymes, The Language of Kathlamet Chinook. PhD dissertation. Indiana University, 1955.