In 1849, the Corps of Topographical Engineers commissioned Lieutenant James H. Simpson to undertake the first survey of Navajo country in present-day New Mexico. Accompanying Simpson was a military force commanded by Colonel John M. Washington, sent to negotiate peace with the Navajo. A keen observer, Simpson kept a journal that provided valuable information on the party's interactions with Indians and also about the land's features, including important pueblo ruins at Chaco Canyon and Canyon de Chelly. His careful observations informed subsequent military expeditions, emigrant trains, the...