Choguita RarÃ¡muri (CR; Tarahumara) is an endangered, underdescribed Uto-Aztecan language spoken in northern Mexico, an area where a significant number of languages became extinct without any documentation before the eighteenth century. With its complex morphology, CR provides a unique opportunity to explore critical questions about the nature of the phonology-morphology interface, the interplay between psycholinguistic and distributional factors in agglutinating morphological systems, as well as the reconstruction of the linguistic and cultural past of the Americas. Initial documentation efforts carried out in the past decade have produced a representative sample of video and audio recordings of a wide range of speech genres. This project will quantitatively and qualitatively expand the existing corpus in order to deepen description and analysis of the language towards the completion of a grammatical description of the language. Through language documentation that is increasingly controlled, modeled and produced by community members, the project will provide: (1) a reference grammar linked to an annotated corpus; (2) an analysis of the typologically unusual morphologically conditioned phonological processes of this language; (3) an assessment of the variation in the linguistic structures within the CR speech community, including variation between older, mostly monolingual speakers, and younger, bilingual speakers; and (4) a corpus of transcribed and annotated audio and visual documents available to community members to serve in efforts of reversal of language decline. The annotated corpus will allow conducting novel theoretical studies on the phonological cues of morphological structure in this agglutinating language. As such, this project will contribute to initiating studies of sophisticated and fine-grained phonological and morphological properties in under-described languages of the Americas with similar morphological systems. Both graduate students and undergraduates are involved in this research, and the research will foster the community's efforts to revitalize and fortify language use through involvement of community members. In addition, the research will be of value to understanding the history of land use in the area, a topic that has attracted recent attention.