This comprehensive biography of Gustaf Nordenskiöld by Judith and David Reynolds appears 111 years after his death. It is noteworthy in view of his contributions in different fields: mineralogy, crystallography, arctic exploration, anthropology and scientific photography. Previously known primarily in his home country, Sweden, and in the American Southwest, Nordenskiöld's life and work has deserved broader attention. The Reynolds have placed the achievements of this young scientist in the context of his family and his cultural background. Tragic developments led serendipitously to his meticulous exploration and exquisite documentation of the Mesa Verde culture. An important base for the Reynolds' study is the extensive collection of letters and documents that the family has been pleased to place in the hands of these dedicated and skillful authors. Nordenskiöld, in addition to his monumental study of the Mesa Verde cliff dwellings, published a brief popular account in Swedish of his travels in the Far West. His Mesa Verde travel journal was compiled and translated by my father, Dr. Olof Arrhenius, and used by Florence and Robert Lister in their informal publication Stones Speak and Waters Sing. However, the full record of Nordenskiöld's life is presented here by the Reynolds for the first time The Reynolds have matched private sources with far-reaching archival work in Sweden, Finland and the United States. They have rescued these combined historical records from the dust of the past and rendered them as a vivid and captivating life story. The family of my maternal grandfather, Gustaf Nordenskiöld, is deeply grateful to the Reynolds for their achievement and together with the scientific community celebrate the appearance of this biography in 2006, the centennial year of Mesa Verde National Park. -- Gustaf Arrhenius Scripps Institution of Oceanography, La Jolla, California, January 18, 2006