The process of rapid development of the ethnological research, taking place currently, necessitated the search for new sources. Among them, of a great value are the records from expeditions of researchers of the past, which bear witness to the ethnographic realities of the respective time. From this point of view, the field notes (notebooks and journals) of Rail Gumerovich Kuzeev (1929–2005) — an outstanding Russian ethnologist, founder of the ethnographic sciences in Bashkortostan, who greatly contributed to the development of the problems of ethnogenesis and ethnic history of the Bashkirs and other Turkic peoples,— have priceless scientific value. The field records from the expeditions of the scientist in 1953–1982 to all major ethnographic and local groups of the Bashkirs are now reposited in the Scientific Archive of the Ufa Federal Research Center of the Russian Academy of Sciences. The notes are made in special notebooks issued by the Academy of Sciences of the USSR for documenting materials of expeditions. In addition to the text (narration of observations, description of ethnographic objects and phenomena, transcripts of conversations with informants, etc.), they also contain many graphic representations (drawings, plans, diagrams). The notes and drawings are made in ink and pencil; in the latest documents, with a ballpoint pen. The aim of the work is to identify their archaeographic features and source-study value (ethnographic and historical evidence, methodology of the scholar's fieldwork). The textual analysis of R.G. Kuzeyev's field notes showed that they captured unique information on the history and ethnography of the Bashkir people, concerning ethnogenesis, migration, tribal structure, ancestral symbols, genealogies, social organization, land ownership, arts and crafts, clothing and ornaments, dwelling, economic activities and trades, traditional festivals and ceremonies, and toponyms. From the source-study perspective, they are of obvious interest to the ethnologists, ethnographers, and socio-cultural anthropologists, as well as to the folklorists (they contain texts of many historical and toponymic legends and tales), archaeologists, especially those dealing with the ‘archaeology of the modern period’ (there is information about old Bashkir settlements, summer camps, abandoned cemeteries), local historians and genealogists (information about history of the settlements, generation lists), etc.