Complex sentence: She was a mainstream Christian during her youth, but eventually joined the Peyote religion, and her autobiography, Mountain Wolf Woman, is credited with bringing whites their first insights into the practice, as well as being a first-hand depiction of native life.
Split into simpler sentences: She was a mainstream Christian during her youth but eventually joined the Peyote religion. Her autobiography, Mountain Wolf Woman, is credited with bringing whites their first insights into the practice, as well as being a first-hand depiction of native life.