Deloria met
Franz Boas while at Teachers College, and began a professional association with him that lasted until his death in 1942. She worked with
Margaret Mead and
Ruth Benedict, anthropologists who had been graduate students of Boas. For her work on American Indian cultures, she had the advantage of fluency in the Dakota,
Lakota, and
Nakota dialects of
Sioux, in addition to
English and
Latin. Therefore, "exam[ining] Deloria's reciprocal mentoring relationships, in this way intervening in previous scholarship’s emphasis upon Deloria’s cultural mediation and personal hardships to highlight her impact on the field of anthropology (...) was instrumental in bringing about important advances to the field." In 1938–39, Deloria was one of a small group of researchers commissioned to do a socioeconomic study on the
Navajo Reservation for the
Bureau of Indian Affairs; it was funded by the
Phelps Stokes Fund. They published their report, entitled
The Navajo Indian Problem. This project opened the door for Deloria to receive more speaking engagements, as well as funding to support her continued important work on Native languages. In 1940, she and her sister Susan went to
Pembroke, North Carolina to conduct some research among the
Lumbee of
Robeson County. Deloria believed she could make an important contribution to their effort for recognition by studying their distinctive culture and what remained of their original language. In her study, she conducted interviews with a range of people in the group, including women, about their use of plants, food, medicine, and animal names. She came very close to completing a dictionary of what may have been their original language before they adopted English. She also assembled a pageant with, for and about the Robeson County Lumbee in 1940 that depicted their origin account. Deloria received grants for her research from Columbia University, the
American Philosophical Society, the
Bollingen Foundation, the
National Science Foundation, and the
Doris Duke Foundation, from 1929-1960s. She was compiling a Lakota dictionary at the time of her death. Her extensive data has proven invaluable to researchers since that time. ==Legacy and honors==