The paper reports on the interim findings of the project “Comprehensive documentation and archiving of Teleut, Eushta-Chat, and Melets Chulym: Three areally adjacent, critical¬ly endangered Turkic languages of Siberia”, documenting the lesser described indigenous mi¬nority idioms in southwestern Siberia. The reported phase of the project was dedicated to local assessment of the languages’ functional spheres and the sociolinguistic makeup of the communities. The results of fieldwork data collection and preliminary analysis confirm that all three languages display unique features differentiating them from the larger Turkic lan-guages in the region: Shor, Tatar and Khakas. All three idioms under study exemplify com¬plex situations of local language contact, variation and change in a context of multilingual¬ism and ongoing cultural shift, as well as demonstrating various stages of en¬dangerment, with Melets Chulym being nearly extinct, and Eushta-Chat and Teleut seriously endan¬gered.