Ella Cara Deloria devoted much of her life to the study of the language and culture of the Sioux (Dakota and Lakota). The Dakota Way of Life is the result of the long history of her ethnographic descriptions of traditional Dakota culture and social life. Deloria was the most prolific Native scholar of the greater Sioux Nation, and the results of her work comprise an essential source for the study of the greater Sioux Nation culture and language. For years she collected material for a study that would document the variations from group to group. Tragically, her manuscript was not published during her lifetime, and at the end of her life all of her major works remained unpublished.

Deloria was a perfectionist who worked slowly and cautiously, attempting to be as objective as possible and revising multiple times. As a result, her work is invaluable. Her detailed cultural descriptions were intended less for purposes of cultural preservation than for practical application. Deloria was a scholar through and through, and yet she never let her dedication to scholarship overwhelm her sense of responsibility as a Dakota woman, with family concerns taking precedence over work. Her constant goal was to be an interpreter of an American Indian reality to others. Her studies of the Sioux are a monument to her talent and industry.