This study examines language contact among Matsigenka, Quechua, and Spanish in Yokiri, a small coffee-producing frontier community on the Andean-Amazonian borderland of Southern Peru. The community was formed by the intermarriage of Andean agricultural migrants and Matsigenka people from a wide variety of places and circumstances across the region, including a Dominican mission and a handful of Andean colonist plantations that used enslaved Matsigenkas for labor. Yokiri is therefore the site of profound linguistic and cultural variation, and the community members have very different experiences with commercial agriculture and orientations to the rural agrarian society. For this reason, Yokiri defies descriptions of Andeans and Amazonians that attribute monolithic ontologies, values, and linguistic repertoires to'ethnic groups' and other imagined human aggregates. To understand this phenomenon, this study examines how language is used in three major interactional contexts in Yokiri (public meetings, negotiations with coffee merchants, and talk in the home and fields), and how each of these communicative domains is tied to different ideologies that regiment the patterns of language use. Language choice and code-switching are central to how the people of Yokiri are negotiating their place within the agrarian society that has emerged around them. A number of linguistic changes have arisen from this profound and intimate multilingualism, including the restructuring of the Matsigenka noun classification system, the borrowing of Spanish discourse markers in both Quechua and Matsigenka, and the circulation of 1) a poetic device used in narrative performance, and 2) reportative evidentiality (a grammatical resource for marking second-hand information). This analysis suggests that Yokiri is an incipient'discourse area', in which areally-distributed pragmatic phenomena cross-cut genetic linguistic groupings. In this sense, Yokiri is similar to other places in South America where widespread multilingualism has led to localized areas of discursive and structural convergence; however, this study challenges the prevailing scholarly and popular view of Andeans and Amazonians as radically separate in cultural, social, and linguistic terms, and proposes that inter-indigenous language contact is as common between macro-geographical regions such as the Andes and Amazonia as within them.