The chapter depicts the work and life of técnicos and their employees and families—many of them ejidatarios (members of ejidos)—on the Nazas River Dam construction site from 1936 to 1946. It begins with the trials and tribulations of técnicos doing the preliminary reconnaissance work in hot and arid conditions around the dam site deep in the Sierra Madre of Durango. It describes how the National Irrigation Commission tried to make the site into an exemplary “company town” that reached a population peak of thirteen thousand and featured socially stratified housing, schools, hospitals, and sports and cultural facilities. It then shows the striking parallels between the town and water-deprived ejidos, many of whose members worked on the dam.