"Your head is round, not flat like ours," a Navajo told Marietta Palmer Wetherill. "You will remember and tell our story to the white man." In the years after she moved to Chaco Canyon in 1897 with her husband, Richard, Marietta Wetherill got to know the Navajo probably as intimately as a white person could. When her husband was murdered by a Navajo in 1910 in the midst of an interracial conflict, Marietta was spared because the Navajo considered...