Witsuwit'en is an endangered First Nations language spoken in western-central British Columbia. A member of the Athapaskan family of languages, the language had been known to have some intriguing characteristics of consonant-vowel interaction, the details of which have been in dispute among scholars. Witsuwit'en Grammar presents acoustic studies of several aspects of Witsuwit'en phonetics, including vowel quality, vowel quantity, ejectives, voice quality, and stress. Information about the sound system and word structure of Witsuwit'en is also provided, revealing many unusual features not previously described in this level of detail for an Athapaskan language. Witsuwit'en has elaborate morphology, even by the standards of the Athapaskan language family. Witsuwit'en Grammar will be of interest to anthropologists interested in the history of the Athapasakan language family, linguists interested in comparative Athapaskan grammar, or any linguist interested in phonetics-phonology or phonology-morphology interaction.