Raised in a sheltered, puritanical household in New England, Elaine Goodale Eastman (1863-1953) followed her conscience and calling in 1885 when she traveled west and opened a school on the Great Sioux Reservation in South Dakota. Over the next six years she witnessed many of the monumental events that affected the Lakotas, including the inception of the Ghost Dance religion and the fallout from the Wounded Knee massacre in December 1890. She also fell in love with and married Charles Eastman, a Dakota doctor with whom she had six children, and went on to help edit his many popular books on Sioux life and culture.   This biography draws on a newly discovered cache of more than one hundred letters from Elaine that were collected by one of her sisters, Rose Goodale Dayton, as well as newly discovered family correspondence and photographs. Previous books about Elaine--including her own autobiography--emphasize her work on the Sioux reservation and association with her famous husband. Access to her personal papers, however, enabled Theodore D. Sargent to shed new light on the dynamics of her thirty-year marriage to Charles and its ultimate demise, the importance of her own literary contributions during this period, and the challenges and successes of her life following their separation. The result is a long overdue multidimensional portrait of the relationships and aspirations that impelled and troubled this fascinating woman and her extraordinary life.